KKILtY 

iRARY 


STATE  OF  ILLINOIS 

STATE  GEOLOGICAL  SURVEY 
FRANK  W.  DEWOLF,  DIRECTOR 


MONOGRAPH  1 


THE 
MISSISSIPPIAN  BRACHIOPODA 


OF  THE 


MISSISSIPPI  VALLEY  BASIN 

PLATES 

BY 

STUART  WELLER 


ILLINOIS 

STATE  GEOLOGICAL  SURVEY 

URBANA 

1914 


EARTH 

SCIENCES 


CAMERON,  AM  BERG  SCO.  PRINTERS,  CHICAGO. 


Plates  and  Explanations 


(All   figures   are   natural    size   unless   otherwise   indicated.) 

The  collection  in  which  each  specimen  used  for  illustration 
may  be  found,  has  been  indicated  in  the  explanation  of  the 
plates.  The  abbreviations  used  are  as  follows : 

W.  M. — Collection  of  Walker  Museum,  University  of  Chicago. 

U.  M. — Collection  of  the  University  of  Michigan. 

A.  M.  N.  H. — Collection  of  the  American  Museum  of  Natural 

History,  New  York. 
U.  S.  N.  M. — Collection  of  the  United  States  National  Museum, 

Washington,  D.  C. 

I.  S.  M. — Collection  of  the  Illinois  State  Museum,  Springfield,  111. 
R.  R.  R. — Collection  of  R.  R.  Rowley,  Louisiana,  Mo. 
D.  K.  G. — Collection  of  D.  K.  Greger,  Columbia,  Mo. 
F.  A.  S. — Collection  of  F.  A.  Sampson,  Columbia,  Mo. 


727528 


EXPLANATION  OF  PLATE  I. 

Figs.  1-2.     LINGULA    GORBYI    Miller p.  35 

Views  of  two  separate  valves.     (W.  M.,  Nos.  9653  and  9654.) 
Choutean  limestone,  Pettis  County,  Missouri. 

Fig.  3.    LINGULA  LOUISIANENSIS  n.  sp p.  34 

View  of  a  single  valve,  the  holotype.     (D.  K.  G.,  No.  1901.) 
Louisiana  limestone,  Louisiana,  Missouri. 

Fig.  4.     LINGULA    HALLI    White p.  35 

View  of  a  single  valve,  the  holotype.     (U.  M.,  No.  1691.) 
Burlington  limestone,  Burlington,  lozva. 

Fig.  5.     LINGULA   MEMBRANACEA   Winchell p.  33 

View  of  a  single  valve,  the  holotype.     (U.  M.,  No.  1330.) 
Chonopectus  sandstone,  Burlington,  Iowa. 

Fig.  6.     LINGULA  VARSOVIENSIS  Worthen p.  36 

View  of  a  single  valve,  the  holotype.     (I.  S.  M.,  No.  2601.) 
Warsaw  beds,  IVarsaiv,  Illinois. 

Fig.  7.     LINGULA  INDIANENSIS  Miller  &  Gurley p.  37 

View  of  a  single  valve,  the  holotype.     (W.  M.,  No.  6187.) 
Crawfordsville  shale,  Crawfordsville,  Indiana. 

Fig.  8.     LINGULA  sp. 

View  of  an  imperfect  valve.     (W.  M.,  No.  7885.) 
Chester  group,  Chester,  Illinois. 

Fig.  9.    LINGULA  sp. 

View  of  an  imperfect  specimen.     (W.  M.,  No.  14497.) 
St.  Louis  limestone,  Monroe  County,  Illinois. 

Fig.  10.     BARROISELLA  SUBSPATULATA   (Meek  &  Worthen). 

View  of  a  single,  very  perfect  valve.     (W.  M.,  No.  7887.) 
Devonian  black  shale,  Union  County,  Illinois. 

Fig.  11.     GLOSSINA  SEDALIENSIS    (Miller) p.  37 

View  of  an  incomplete  valve  with  the  outline  restored.      (W.   M., 
No.  9652.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

Fig.  12.     GLOSSINA  LINEOLATA   (Rowley) , p.  38 

View  of  a  single  valve,  one  of  the  cotypes.     (R.  R.  R.) 
Louisiana  limestone,  Louisiana,  Missouri. 

Fig.  13.     ORBICULOIDEA  CAPAX   (White)    p.  39 

View   of   the   holotype,   an   imperfect   brachial   valve.      (U.   M.,    No. 
1331.) 

Chonopectus  sandstone,  Burlington,  Iowa. 

Figs.  14-17.     ORBICULOIDEA  KEOKUK   (Gurley) p.  41 

14-15.     Views  of  the  cotypes  of  the  species,  a  pedicle  and  a  brachial 
valve.     (W.  M.,  No.  6331.)     16-17.    Views  of  two  pedicle  valves, 
one  external  and  the  other  internal.     (W.  M.,  No.  14787.) 
Crawfordsville  shale,  Crawfordsville,  Indiana. 

Fig.  18.     ORBICULOIDEA  sp. 

View  of  a  very  perfect  brachial  valve.     (W.  M.,  No.  12281.) 

Productus  magnus  bed,  Ste.  Genevieve  County,  Missouri. 

5 


Figs.  19-20.     ORBICULOIDEA   BATESVILLENSIS   Weller p.  42 

Views  of  the  internal  casts  of  two  brachial  valves,  the  cotypes. 
(W.  M.,  No.  4963.) 

Batesville  sandstone,  Batesville,  Arkansas. 

Figs.  21-22.     ORBICULOIDEA  SAMPSONI   (Miller)    p.  40 

21.     View  of  a  brachial  valve,  the  holotype.      (W.   M.,   No.  6962.) 
22.     View  of  another  brachial  valve.     (W.  M.,  No.  9674.) 
Chouteau  limestone,  Sedalia,  Missouri. 

Figs.  23-24.     ORBICULOIDEA  VARSOVIENSIS   (Worthen) p.  41 

Views  of  the  cotypes.  24.  A  nearly  complete  pedicle  valve  from  the 
inner  side.  23.  Two  much  crushed  valves  upon  a  fragment  of 
limestone.  (I.  S.  M.,  No.  2545.) 

Keokuk  limestone,  Warsaw,  Illinois. 

Figs.  25-26.     CRANIA  REPOSITA  White p.  44 

25.    View  of  four  specimens  of  pedicle  valves  attached  to  a  shell  of 
Spirifer  grimesi.    26.    View  of  a  fourth  individual  from  another 
portion  of  the  same  -S\  grimesi.    Cotypes.     (U.  M.,  No.  1692.) 
Burlington  limestone,  Burlington,  Iowa. 

Figs.  27-29.     CRANIA  CHESTERENSIS  Miller  &  Gurley p.  45 

Views  of  the  cotypes,  attached  to  the  bases  of  the  bryozoan  Lyrio- 
pora,  and  to  a  shell  of  Spirifer.     (W.  M.,  No.  6067.) 
Chester  beds,  Chester,  Illinois. 

Fig.  30.     CRANIA   MISSOURIENSIS  Weller p.  43 

Exterior  view  of  a  brachial  valve,  the  holotype.  (W.  M.,  No. 
13902.) 

Fern  Glen  formation,  Fern  Glen,  Missouri. 

Fig.  31.     CRANIA  SPICULATA  Rowley p.  47 

View  of  a  brachial  valve,  the  holotype.     (R.  R.  R.) 
Louisiana  limestone,  Louisiana,  Missouri. 

Fig.  32.     CRANIA   DODGEI    Rowley p.  44 

View  of  a  brachial  valve,  the  holotype.     (R.  R.  R.) 
Louisiana  limestone,  Louisiana,  Missouri. 

Fig.  33.     CRANIA  L,EVIS   Keyes p.  47 

View  of  a  brachial  valve,  one  of  the  cotypes.     (R.  R.  R.) 
Burlington  limestone,  Louisiana,  Missouri. 

Figs.  34-36.     CRANIA  BLAIRI   Miller p.  46 

34-35.  External  and  internal  views  of  a  brachial  valve.  (W.  M., 
No.  9675.)  36.  View  of  a  large  brachial  valve.  (W.  M.,  No. 
14310.) 

Chouteau   limestone,   Pettis    County   and   Providence,   Mis- 
souri. 

Figs.  37-39.     CRANIA  ROWLEYI  Gurley p.  46 

View  of  a  brachial  valve,  the  holotype.  (W.  M.,  No.  6316.) 
38-39.  Views  of  two  other  brachial  valves.  (W.  M.,  Nos.  11895 
and  13060.) 

Louisiana  limestone,  Louisiana,  Missouri. 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  I. 


34 


39 


EXPLANATION  OF  PLATE  II. 

Figs.  1-10.    LEPT^ENA  ANALOGA  (Phillips) , p.  49 

1-2.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
3-4.  External  and  internal  views  of  another  smaller  pedicle 
valve.  (W.  M.,  No.  4696.) 

Fern  Glen  formation,  near  Kimmswick,  Missouri. 
5-6.    Internal  and  external  views  of  a  nearly  complete  brachial  valve. 
(W.  M.,  No.  9719.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

7-9.     Pedicle,   lateral   and   profile   views   of    a   nearly   complete   but 
somewhat  distorted  specimen.     (W.  M.,  No.  7055.) 
Chouteau  limestone,  Green  County,  Missouri. 

10.  View  of  the  internal  cast  of  a  pedicle  valve.     (W.  M.,  347.) 

Lower  Burlington  limestone,  near  Springfield,  Missouri. 

Figs.  11-16.    LEPTVENA  CONVEXA  n.  sp p.  52 

11.  External  view  of  a  brachial  valve,  and  12,  external  view  of  a 
pedicle  valve,  in  which  the  geniculate  curvature  of  the  shell  is 
wanting.     (W.  M.,  No.  13356.) 

Kinderhook,  Bed  No.  6,  Burlington,  Iowa.    . 

13.  Internal  cast  of  a  pedicle  valve,  and  14,  the  impression  of  the 
external  surface  of  a  brachial  valve.  (W.  M.,  No.  6659.) 

Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 

15-16.  Two  views  of  a  pedicle  valve  in  which  the  geniculation  of  the 
shell  is  absent.  (W.  M.,  No.  13357.) 

Kinderhook  oolite,  Burlington^,  Iowa. 

,F,igs.  17-18.     STREPTORHYNCHUS  ULRICHI  Hall  &  Clarke p.  73 

External  and  internal  views  of  a  pedicle: valve,  the  holotype.  (U.  S. 
N.  M.,  No.  44994.) 

Chester  group,  2  miles  east  of  Scottsburg,  Kentucky. 

Figs.  19-22.     SCHUCHERTELLA  cosxATULA  (Hall  &  Clarke) p.  57 

19-20.  Brachial  and  pedicle  views  of  a  nearly  complete  specimen, 
the  holotype.  21-22.  External  and  internal  views  of  an  incom- 
plete pedicle  valve,  the  latter  showing  the  entire  absence  of  a 
median  septum.  (W.  M.,  No.  14498.) 

Chester  group,  Crittenden  County,  Kentucky. 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  II. 


22 


16 


EXPLANATION  OF  PLATE  III. 

FigS.    1-9.       SCHUCHERTELLA    LENS     (White) p.    55 

1-3.  Brachial,  pedicle  and  posterior  views  of  a  nearly  perfect  speci- 
men. 4.  Brachial  view  of  another  nearly  perfect  specimen. 
(W.  M.,  No.  6693.)  5-6.  Exterior  and  interior  views  of  a  very 
perfect  pedicle  valve.  7.  Interior  view  of  a  brachial  valve. 
8.  Interior  view  of  a  pedicle  valve.  (W.  M.,  No.  13051.) 

Louisiana  limestone,  Louisiana.  Missouri. 
9.    View  of  a  large  brachial  valve.     (W.  M.,  No.  14258.) 
Louisiana  limestone,  Calhoun  County,  Illinois. 

Figs.  10-11.     SCHUCHERTELLA  RUBRA  Weller p.  56 

Brachial  and  pedicle  views  of  the  holotype.     (W.  M.,  No.  13911.) 
Fern  Glen  formation,  near  Kimmswick,  Missouri. 

Figs.  12-13.     SCHUCHERTELLA  FERNGLENENSIS  n.  sp p.  54 

Pedicle  and  brachial  views  of  a  nearly  complete  but  somewhat  dis- 
torted specimen,  the  holotype.     (W.  M.,  No.  13910.) 
Fern  Glen  formation,  Fern  Glen,  Missouri. 

FigS.    14-16.      SCHELLWIENELLA    IN.EQUALIS     (Hall) p.   61 

14.  A  nearly  complete  internal  cast  of  a  brachial  valve.  (\V.  M., 
No.  6662.)  15-16.  Two  nearly  complete  internal  casts  of  pedicle 
valves.  (W.  M.,  Nos.  14755  and  14754.) 

Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 

Figs.  17-18.     SCHELLWIENELLA  CRENULICOSTATA  n.  sp p.  63 

17.  View  of   a  very  perfect  pedicle  valve,  the  holotype.      (W.   M., 
No.  14233.) 

Kinderhook  oolite,  Bed  No.  6,  Burlington,  Iowa. 

18.  View  of  a  modified  internal  cast  of  a  nearly  complete  pedicle 
valve  probably  belonging  to  this  species.     (W.  M.,  No.  14499.) 

Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 

Figs.  19-22.     SCHELLWIENELLA  PLANUMBONA  n.  sp p.  65 

19-20.  Two  nearly  complete  but  more  or  less  exfoliated  pedicle 
valves.  (W.  M.,  No.  14756.)  21-22.  Two  incomplete  and  more 
or  less  exfoliated  brachial  valves.  (W.  M.,  Nos.  6671  and 
14756.)  Cotypes. 

Kinderhook  oolite,  Bed  No.  6,  Burlington,  Iowa. 


10 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  III. 


EXPLANATION  OF  PLATE  IV. 

FigS.    1-2.      SCHELLWIENELLA    BURLINGTONENSIS    n.    Sp ..p.   67 

1.     View  of  a  large,  partially  exfoliated  pedicle  valve.    2.     View  of 
a  smaller,  somewhat  crushed  brachial  valve.     Cotypes      (W    M 
No.  13354.) 

Burlington  limestone,  Henderson  County,  Illinois. 

Figs.  3-5.     STREPTORHYNCHUS  TENUICOSTATUM  n.  sp p.  69 

3-4.      Pedicle    and    brachial    views    of    a    nearly    complete    example. 
5.     View  of  an  exfoliated  brachial  valve.     Cotypes      (W    M 
No.  9665.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 

Fig.  6.     SCHELLWIENELLA  ALTERNATA  n.  sp p.  66 

View  of  a  nearly  complete  but  somewhat  exfoliated  brachial  valve, 
the  holotype.  (W.  M.,  No.  13355.) 

Burlington  limestone,  Burlington,  Iowa. 

Figs.  7-12.     SCHELLWIENELLA  INFLATA  (White  &  Whitfield) p.  59 

7-9.  Pedicle,  lateral  and  brachial  views  of  a  sulphur  cast  of  one  of 
the  cotypes.  (W.  M.,  No.  14218.) 

Kinderhook,  Bed  No.  6,  Burlington,  Iowa. 

10.  View  of  an  internal  cast  of  a  nearly  complete  brachial  valve. 
(W.  M.,  No.  13355.)  11-12.  Brachial  and  lateral  views  of  a 
nearly  complete  internal  cast  of  a  brachial  valve,  one  of  the 
cotypes.  (U.  M.,  No.  1353.) 

Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 


\2 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 

^BB^K 

•  *  / 

• 


MONOGRAPH  No.  1.    PLATE  IV. 


-.«.•"     '      /,M 


EXPLANATION  OF  PLATE  V. 

Figs.  1-19.     STREPTORHYNCHUS  RUGINOSUM   (Hall  &  Clarke) p.  71 

1-5.     Pedicle,  brachial,  lateral,  posterior,  and  anterior  views  of  the 
holotype.     (W.  M.,  No.  11912.) 

St.  Louis  chert,  Providence,  Indiana. 

6-9.     Pedicle,  brachial,  posterior,  and  lateral  views  of  a  nearly  com- 
plete specimen.     (W.  M.,  No.  10129.) 

St.  Louis  limestone,  St.  .Louis,  Missouri. 

10-11.     View  of  an  internal  cast,  and  a  plaster  cast  of  the  natural 
mould    of    the    exterior    of    the    same    specimen.      One    of    the 
cotypes  of  S.  williamsi  Weller.     (W.  M.,  No.  4956.) 
Baicsville  sandstone,  Batesville,  Arkansas. 

12.  View  of  a  pedicle  valve.     (W.  M.,  No.  14759.) 

St.  Louis  limestone,  Alton,  Illinois. 

13.  View  of  an  internal  cast  of  a  nearly  complete  brachial  valve. 
14.     View  of  an  internal  cast  of  a  pedicle  valve.     (W.  M.,  No. 
14758.) 

Salem  limestone,  Hull's  Hollow,  near  Alton,  Illinois. 
15.    View  of  the  internal  cast  of  a  small  pedicle  valve.     16.    View  of 
the  internal  cast  of  a  brachial  valve.     (W.  M.,  No.  282.) 

Residual  chert,  Springfield,  Missouri. 

17-18.     Pedicle  and   brachial  views  of   a  nearly  complete   specimen. 
(W.  M.,  No.  10922.) 

St.  Louis  limestone,  Alton,  Illinois. 

19.    View  of  a  nearly  complete  pedicle  valve.     (W.  M.,  No.  10129.) 
St.  Louis  limestone,  St.  Louis,  Missouri. 


14 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  V. 


EXPLANATION  OF  PLATE  VI. 

Figs.  1-14.     ORTHOTETES   KASKASKIENSIS   McChesney p.  77 

1-4.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly  com- 
plete specimen.  5-8.  Pedicle,  brachial,  posterior  and  lateral 
views  of  a  smaller  example.  (W.  M.,  No.  10920.) 

Pella  beds,  Pella,  Iowa. 

13-14.  Pedicle  and  brachial  views  of  a  nearly  complete  example. 
(VV.  M.,  No.  8647.) 

Chester  group,  Meade  County,  Kentucky. 

9-12.  Brachial,  pedicle,  posterior  and  lateral  views  of  a  nearly  com- 
plete specimen.  (W.  M.,  No.  8648.) 

Chester  group,  Randolph  County,  Illinois. 

Fig.  15.     ORTHOTETES  KASKASKIENSIS  McChesney   (?) p.  77 

View  of  a  nearly  complete  but  exfoliated  brachial  valve  which  differs 
from  the  more  typical  representatives  of  the  species  in  having 
much  stronger  costae  at  regular  intervals.     (W.  M.,  14760.) 
Chester  group,  Red  Bud,  Illinois. 

Figs.  16-21.     STREPTORHYNCHUS  MINUTUM  Cumings p.  70 

16-18.     Pedicle,  brachial  and  posterior  views  of  a  complete  example 
(x4).     19-21.  Similar  views  of  another  example  (x4).    (W.  M.) 
Salem   limestone,  Bloomington,  Indiana. 


16 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  VI. 


EXPLANATION  OF  PLATE  VII. 

Figs.  1-4.     ORTHOTETES  KEOKUK  Hall p.  75 

1-3.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  but 
exfoliated  specimen.  (W.  M.,  No.  8652.) 

Keokuk  limestone,  Keokuk,  Iowa. 

4.    View  of  an  incomplete  internal  cast  of  a  pedicle  valve  showing 
the  median  septum  as  a  slit.     (W.  M.,  No.  363.) 
Residual  chert,  Springfield,  Missouri. 

FigS.    5-8.       SCHELLWIENELLA    CHOUTEAUENSIS    n.    Sp p.    64 

5-6.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
7-8.  Brachial  view  of  another  less  complete  specimen.  Cotypes. 
(W.  M.,  No.  9856.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

FigS.    9-10.       SCHUCHERTELLA    Sp. 

Views  of  two  imperfect  pedicle  valves.     (W.  M.,  No.  11353.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 


IS 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  VII. 


EXPLANATION    OF    PLATE   VIII. 

Figs.  1-7.     CHONETES  SHUMARDANUS  DeKoninck p.  89 

1.  Pedicle  valve  of  a  large  individual.  2-3.  Pedicle  and  brachial 
views  of  a  specimen  preserving  both  valves.  4-5.  Pedicle  and 
brachial  views  of  another  specimen  preserving  both  valves. 
6-7.  Exterior  and  interior  views  of  a  pedicle  valve.  (W.  M., 
No.  13940.) 

New  Providence  shale,  Button  Mould  Knob,  Kentucky. 

Figs.  8-16.     CHONETES    MULTICOSTA    Winchell p.  79 

8-9.     Pedicle  and  brachial  views  of  a  large  example  preserving 
both  valves.     (W.  M.,  No.  4700.) 

Fern   Glen  formation,  Fern  Glen,  Missouri. 

10-11.     Views    of    two    large    pedicle    valves.     (W.    M.,    No.    352.) 
Burlington    limestone,   near   Springfield,  Missouri. 

12.  View  of  a  pedicle  valve,  the  principal  one  of  Winchell's  types. 
(U.  M.,  No.  1343.) 

Lo-ii'er  Burlington   limestone   (?),  Burlington,  Iowa. 

13.  View  of   a  brachial  valve,   one  of   Winchell's  types.     (U.   M., 
No.  1343.) 

White  chert,  probably  from  the  Lozver  Burlington  limestone, 
Burlington,  lozva. 

14-15.     External     impressions     of     two     brachial     valves.     16.     An 
internal  cast  of  a  pedicle  valve.     (U.  M.,  No.  1343.) 
Kinderhook,  bed  No.  7,  Burlington,  Iowa. 

Fig.  17.     CHONETES  sp. 

The  internal  cast  of  a  pedicle  valve  included  among   the  types  of 
C.  multicosta  Winchell.     (U.  M.,  No.  1343.) 
Chonopcctits  sandstone,  Burlington,  Iowa. 

Figs.  18-19.     CHONETES    BURLINGTONENSIS    Weller p.  93 

18.  View  of  a  pedicle  valve,  the  holotype.     (W.  M.,  No.  6669.) 

19.  View  of  a  brachial  valve.     (W.  M.,  No.  13943.) 

Kinderhook  oolite,  bed  Aro.  6,  Burlington,  Iowa. 

Fig.  20.     CHONETES  MISSOURIENSIS  n.  sp p.  82 

View  of  a  large  pedicle  valve,  the  holotype.     (W.   M.,  No.  8560.) 
Pierson  limestone,  near  Springfield,  Missouri. 

Figs.  21-29.     CHONETES   ORNATUS    Shumard p.  86 

21-24.  Pedicle  views  of  four  nearly  perfect  individuals. 
25-28.  Brachial  views  of  the  same  four  individuals. 
29.  View  of  the  interior  of  a  brachial  valve.  (W.  M., 
No.  6726.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Fig.  30.     CHONETES    GLENPARKENSIS    Weller p.  87 

View  of  a  pedicle  valve,  the  holotype.     (W.  M.,  No.  11355.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 

21 


Figs.  31-34.    CHONETES  CHESTERENSIS  n.  sp p.  83 

33-34.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
Cotype.  (W.  M.,  No.  7693.) 

Chester    group,   Monroe    County,   Illinois. 

31-32.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
Cotype.  (W.  M.,  No.  14761.) 

Chester  group,  St.  Clair  County,  Illinois. 

Figs.  35-42.     CHONETES  GENICULATUS   White p.  92 

35-38.  Pedicle  views  of  four  nearly  complete  individuals. 
39-42.  Views  of  the  same  four  individuals  from  the  brachial 
side.  (W.  M.,  No.  6727.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  43-46.     CHONETES  LOGANI  Norwood  &  Pratten p.  84 

43-44.  Views  of  two  pedicle  valves.  45-46.  Views  of  two  brachial 
valves.  (W.  M.,  No.  13941.) 

Kinderhook  oolite,  bed  No.  6,  Burlington,  Iowa. 

Figs.  47-49.     CHONETES    GLENPARKENSIS    Weller p.  87 

Views  of  three  pedicle  valves.     (W.  M.,  No.  9721.) 

Chouteau    limestone,   Pcttis  County,   Missouri. 

Figs.  50-55.     CHONETES  sp. 

50-52.     External    views    of    three    somewhat    worn    pedicle    valves. 
53.     Exterior  view  of  a  brachial  valve.     54-55.     Internal  views 
of  two  brachial  valves.     (W.  M..  No.  11354.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 

Figs.  56-57.     CHONETES  sp. 

56.     View  of   the   impression  of  the   exterior   of   a  brachial   valve. 
57.     View  of  a  pedicle  valve.     (W.  M.,  No.  13945.) 
Kinderhook,  bed  No.  3,  Burlington,  Iowa. 

Figs.  58-62.     CHONETES  PLANUMBONA  Meek  &  Worthen p.  94 

58-59.  Pedicle  and  brachial  views  of  a  nearly  perfect  individual. 
60-61.  Similar  views  of  a  second  example.  62.  Brachial  view 
of  a  third  specimen.  (W.  M.,  No.  7684.) 

Kcokuk,  Ste.  Gencvieve  County,  Missouri. 

Figs.  63-70.     CHONETES  ILLINOISENSIS  Worthen p.  81 

63.  Pedicle  view  of  a  nearly  perfect  valve.  64.  View  of  a  group 
of  shells,  one  of  which  is  illustrated  separately  as  fig.  63. 
(W.  M.,  No.  14380.) 

Burlington  limestone,  Boonevillc,  Missouri. 

65.  Pedicle  view.  66.  Brachial  view.  67.  View  of  the  interior 
of  a  brachial  valve.  (W.  M.,  No.  2968.) 

Burlington   limestone,  Springfield,  Missouri. 

68.  Pedicle  view.  69.  Brachial  view.  70.  View  of  the  interior 
of  a  brachial  valve.  (W.  M.,  No.  2969.) 

Keokuk   limestone,   near   Springfield,  Missouri. 

Figs.  71-72.     CHONETES  GREGARIUS  Weller p.  91 

Views  of  two  pedicle  valves.     (W.  M.,  No.  13944.) 
Kinderhook,  bed  No.  3,  Burlington,  Iowa. 

Fig.  73.     CHONOPECTUS   FISCHERI   Norwood   &    Pratten p.  96 

View  of  a  very  perfect  pedicle  valve.     (W.  M.,  No.  6657.) 
Kinderhook,  bed  No.  3,  Burlington,  Iowa. 

22 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  VIII. 


8 


9 


10 


12 


13 


14 


15 


11 


16 


25 


18 


19 


20 


17 


21        22        23         24        3°       31        33 


26         27         28       29          32        34 


J 

35 


* 

36 


37 


J 

38 


r 

39 


r 

40 


42 


43        44        45       46 


47 


Jl   J   J 


5O       51       52        53 


48         49 


54      55       56       57 


73 


EXPLANATION   OF   PLATE   IX. 

Figs.  1-10.     PRODUCTUS  BURLINGTONENSIS   Hall p.  104 

1-3.     Pedicle,    posterior    and    lateral    views    of    a    pedicle    valve. 
4-5.     Pedicle    and    posterior    views    of    another    pedicle    valve. 
(W.  M.,  No.  14303.)     6-8.     Pedicle  lateral  and  posterior  views 
of  a  nearly  perfect  pedicle  valve.     (W.  M.,  No.  14287.) 
Burlington  limestone,  Burlington,  Iowa. 

9.  View  of  a  somewhat  imperfect  specimen  of  the  interior  of  a 
brachial    valve.     (W.    M.,    No.    345.) 

Burlington  limestone,  Springfield,  Missouri. 

10.  View  of  a  nearly  complete   specimen  from  the  brachial  side, 
showing  the  concave  brachial  valve.     (W.  M.,  No.  14288.) 

Burlington  limestone,  Quincy,  Illinois. 

Figs.  11-17.     PRODUCTUS  FERNGLENENSIS  Weller p.  105 

11-13.  Pedicle,  posterior  and  lateral  views  of  a  nearly  complete 
pedicle  valve.  14.  View  of  another  pedicle  valve.  15.  View 
of  a  large  pedicle  valve.  16.  View  of  a  brachial  valve  from 
the  interior,  showing  the  cardinal  process ;  over  the  greater 
portion  of  the  specimen  the  shell  substance  has  been  destroyed 
so  that  an  impression  of  the  exterior  of  the  valve  is  exposed. 
Cotypes.  (W.  M.,  No.  4669.) 

Fern  Glen  formation,  near  Kinnnswick,  Missouri. 
17.     View  of  a  pedicle  valve.     (W.  M.,  No.  8556.) 

Pier  son   limestone,   near  Springfield,  Missouri. 


24 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  IX. 


EXPLANATION  OF  PLATE  X. 

Figs.  1-6.     PRODUCTUS  INFLATUS  McChesney p.  Ill 

1-3.  Pedicle,  posterior  and  lateral  views  of  a  nearly  perfect 
pedicle  valve.  (W.  M.,  No.  14762.) 

Chester  group,  Red  Bud,  Illinois. 

4-6.  Pedicle,  posterior  and  lateral  views  of  a  nearly  perfect  pedicle 
valve.  (W.  M.,  No.  14304.) 

Chester  group,  Meade  County,  Kentucky. 

Figs.  7-13.     PRODUCTUS  MESIALIS  Hall p.  1 12 

7-9.     Pedicle,    posterior    and    lateral    views    of    a    pedicle    valve. 
10-12.     Similar    views    of    another    example.     13.     View    of    a 
natural  impression  of  a  brachial  valve.     (W.  M.,  No.  14329.) 
Chert  from  Keokuk  (?) ,  Pierce  City,  Missouri. 

Figs.  14-24.     PRODUCTUS  ALTONENSIS  Norwood  &  Pratten p.  124 

14.  Posterior  view  of  a  pedicle  valve.     (W.  M.,  No.  14295.) 

Salem  limestone,  S  per  gen  Hill,  Indiana. 

15.  Brachial  view  of   a  nearly   complete    shell.     16-18.     Posterior, 
brachial  and  lateral  views  of  a  nearly  complete  shell.     (W.  M., 
No.  14305.) 

Salem  limestone,  Harrison  County,  Indiana. 

19-21.  Pedicle,  posterior  and  lateral  views  of  a  nearly  complete 
pedicle  valve.  (W.  M.,  No.  3142.) 

Salem  limestone,  Washington  County,  Indiana. 
22-24.     Pedicle,   posterior  and  lateral  views  of   a   nearly  complete 
pedicle  valve.     (W.  M.,  No.   14296.) 

Salem   limestone,  Spergen   Hill,  Indiana. 

Figs.  25-27.     PRODUCTUS   TENUICOSTUS   Hall p.  119 

Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  internal 
cast  of  a  pedicle  valve  which  probably  belongs  to  this  species. 
(W.  M.,  No.  279.) 

Residual  chert,  Springfield,  Missouri. 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  X. 


24 


EXPLANATION   OF   PLATE  XI. 

Figs.  1-5.     PRODUCTUS   TENUICOSTUS   Hall p.  119 

1-3.     Pedicle,  lateral  and  posterior  views  of  a  good  pedicle  valve. 
(W.  M.,  No.  14283.) 

St.  Louis  limestone,  Alton,  Illinois. 

4-5.  Pedicle  and  lateral  views  of  another  pedicle  valve.  (W.  M., 
No.  14284.) 

St.  Louis  limestone,  Milan,  Illinois. 

Figs.  6-11.     PRODUCTUS   VIMINALIS   White p.  114 

6.  Pedicle  view  of  the  holotype,  a  somewhat  crushed  pedicle 
valve.  9-10.  Pedicle  and  lateral  views  of  a  large  pedicle  valve, 
an  authentic  specimen  associated  with  the  holotype  in  the  White 
Collection  at  the  University  of  Michigan.  (U.  M.,  No.  1693.) 

Burlington  limestone,  Burlington,  Iowa. 

9-10.  Pedicle  and  lateral  views  of  a  nearly  perfect  and  undistorted 
pedicle  valve.  (W.  M.,  No.  14291.) 

Burlington  limestone,  Quincy,  Illinois. 

11.  View    of    a    natural    mould    of    the    external    surface    of    the 
brachial    valve,    with    a    portion    of    the    valve,    including    the 
cardinal    process,    adhering    posteriorly.     (W.    M.,    No.    7925.) 

Burlington    limestone,   Springfield,   Missouri. 

Figs.  12-16.     PRODUCTUS  MESICOSTALIS  n.  sp p.  114 

12.  View    of    a    pedicle    valve.      13-15.     Pedicle,    posterior    and 
lateral  views  of  a  pedicle  valve.     16.     Interior  view  of  a  bra- 
chial valve.     (W  M.,  No.  10585.) 

English  River  grit,  Maple  Mill,  Washington  County,  Iowa. 


28 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XL 


EXPLANATION  OF  PLATE  XIII. 

Figs.  1-12.     PRODUCTUS    ARCUATUS    Hall p.  107 

1-3.  Pedicle,  lateral  and  posterior  views  of  a  very  perfect  pedicle 
valve.  4-5.  Pedicle  and  lateral  views  of  a  natural  mould  of 
the  concave  brachial  valve.  (W.  M.,  No.  9823.) 

Chouteau  limestone,  Choutcau  Springs,  Missouri. 
6-8.  Pedicle,  lateral  and  posterior  views  of  a  very  perfect  pedicle 
valve.  (W.  M.,  No.  14285.)  9-10.  Pedicle  and  lateral  views 
of  a  nearly  complete  specimen.  11-12.  Pedicle  and  lateral 
views  of  the  natural  mould  of  the  concave  brachial  valve  of 
the  same  shell.  (W.  M.,  No.  14330.) 

Kinderhook  oolite,  bed  No.  6,  Burlington,  Iowa. 

Figs.  13-17.     PRODUCTUS  WORTHENI  Hall p.  126 

13-15.  Pedicle,  lateral  and  posterior  views  of  a  nearly  perfect 
pedicle  valve.  16.  Pedicle  view  of  a  natural  mould  of  the 
external  surface  of  a  brachial  valve.  (W.  M.,  No.  281.) 

Residual  chert,  Springfield,  Missouri. 

17.     Pedicle  view  of   a  nearly  complete  natural  mould  of   the  ex- 
ternal surface  of  a  brachial  valve.     (W.  M.,  No.  294.) 
Keokuk  limestone,  near  Springfield,  Missouri. 

Figs.  18-23.     PRODUCTUS    MARGINICINCTUS    Prout p.  127 

18-19.     Pedicle  and  brachial  views  of   a  nearly  complete  example. 

20-21.     Pedicle  and  lateral  views  of  a  nearly  complete  pedicle 

valve.     (W.  M.,  No.  10846.)     22-23.     Pedicle  and  lateral  views 

of  another  nearly  complete  pedicle  valve.     (W.  M.,  No.  14290.) 

St.  Louis  limestone,  St.  Louis.,  Missouri. 

Figs.  24-29.     PRODUCTUS  SCITULUS  Meek  &  Worthen p.  120 

24-26.  Pedicle,  lateral  and  posterior  views  of  a  nearly  complete 
pedicle  valve.  (W.  M.,  No.  13128.) 

St.  Louis  limestone,  St.  Louis,  Missouri. 

27-28.  Views  of  two  nearly  perfect  internal  casts  of  pedicle  valves. 
29.  View  of  the  impression  of  the  exterior  of  a  brachial 
valve.  (W.  M.,  No.  14764.) 

St.    Louis    limestone     (chert),    Fountain    Creek,    Monroe 
County,  Illinois. 

Figs.  30-35.     PRODUCTUS  SAMPSON:  Weller p.  129 

30-33.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly 
perfect  shell.  The  holotype.  (W.  M.,  No.  9695.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

34-35.     Views  of  two  larger  pedicle  valves.     (W.   M.,   No.  4698.) 
Fern   Glen  formation,  near  Kiinmswick,  Missouri. 


32 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XIII. 


10 


13 


14 


15 


12  11 


16 


18 


19 


22 


: 

^^ 


23 


24          25         26 


30          31 


32 


20 


21 


27 


28 


29 


33          34 


35 


EXPLANATION  OF  PLATE  XIV. 

Figs.  1-7.     PRODUCTUS  SEDALIENSIS  n.  sp p.  108 

1-2.     Pedicle  and  lateral  views  of  a  large  specimen.      3-5.     Pedicle, 
lateral    and    posterior    views    of    another    smaller    specimen. 
6-7.     Pedicle    and    lateral    views    of    a    natural    mould    of    the 
exterior  of  a  brachial  valve.     (W.  M.,  No.  9691.) 
Chouteau   limestone,  Pettis  County,  Missouri. 

Figs.  8-13.     PRODUCTUS  CURTIROSTRIS  Winchell p.  130 

8-9.  Lateral  and  pedicle  views  of  a  pedicle  valve.  10-11.  Poste- 
rior and  pedicle  views  of  another  pedicle  valve.  Cotypes. 
(U.  M.,  No.  1337.) 

Chonopcctus  sandstone,  Burlington,  Iowa. 

12-13.  Views  of  two  pedicle  valves.  In  fig.  13  the  material  has 
been  broken  away  in  such  a  manner  as  to  exhibit  the  impres- 
sion of  the  brachial  valve.  (W.  M.,  No.  10576.) 

English  River  grit,  Maple  Mill,   Washington   County,  Iowa. 

Figs.  14-21.     PRODUCTUS  BLAIRI  Miller p.  110 

14-16.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete 
specimen.  17-19.  Similar  views  of  another  example.  (W.  M., 
No.  9824.) 

Chouteau    limestone,   Chouteau   Springs,  Missouri. 
20-21.     Pedicle    views    of    the    natural    moulds    of    two    brachial 
valves.     (W.  M.,  No.  9692.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

Figs.  22-23.     PRODUCTUS  sp. 

Pedicle  and  brachial  views  of  a  nearly  complete  shell.  (W.  M., 
No.  9825.) 

Chouteau   limestone,   Chouteau   Springs,  Missouri. 

Figs.  24-25.     PRODUCTUS    PARVULUS    Winchell p.  12S 

Views  of  two  pedicle  valves.     Cotypes.     (U.   M.,   No.   1338.) 
Kinderhook,  bed  No.  5,  Burlington,  Iowa. 

Figs.  26-27.     PRODUCTUS  sp. 

Pedicle  and  lateral  views  of  a  nearly  complete  pedicle  valve. 
(D.  K.  G.,  No.  2101.) 

Burlington  limestone,  Louisiana,  Missouri. 


34 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


17 


MONOGRAPH  No.  1.    PLATE  XIV. 

i 


16 


19 


22 


23 


27 


26 


25  24 


EXPLANATION  OF  PLATE  XV. 

Figs.  1-8.     PRODUCTUS  MAGNUS  Meek  &  Worthen p.  117 

1-3.  Pedicle,  lateral  and  posterior  views  of  a  nearly  complete 
pedicle  valve.  4.  View  of  a  natural  mould  of  the  exterior  of 
brachial  valve.  (W.  M.,  No.  14321.)  5.  Posterior  view  of 
another  example  showing  the  arrangement  of  spine  bases  along 
the  cardinal  margin.  (W.  M.,  No.  14765.) 

Keokuk,  Monroe   County,  Illinois. 

6-8.  Pedicle,  lateral  and  posterior  views  of  a  smaller  example, 
having  the  characters  of  the  shell  described  as  P.  fcutoncnsis 
by  Shumard.  (W.  M.,  No.  14308.) 

Keokuk,  Fenton,  St.  Louis  County,  Missouri. 


36 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XV. 


EXPLANATION  OF  PLATE  XVI. 

Figs.  1-15.     PRODUCTUS  OVATUS  Hall p.  132 

1-3.  Pedicle,  lateral  and  posterior  views  of  a  nearly  complete 
pedicle  valve.  (Productus  pileiformis.)  (W.  M.,  No.  14323.) 

Chester  group,  Chester,  Illinois. 

4-5.  Pedicle  and  lateral  views  of  a  pedicle  valve.  6-7.  Direct 
and  profile  views  of  the  external  impression  of  a  brachial  valve. 
(Productus  pileiformis.)  (W.  M.,  No.  14314.) 

Chester  group,  Meade  County,  Kentucky. 

8-9.  Pedicle  and  lateral  views  of  a  nearly  complete  pedicle 
valve.  (W.  M.,  No.  326.)  , 

Keokuk  limestone,  near  Springfield,  Missouri. 

10-11.  Pedicle  and  lateral  views  of  a  nearly  complete  pedicle 
valve.  (W.  M.,  No.  10130.) 

St.  Louis  limestone,  St.  Louis,  Missouri. 

12.  Direct  view  of  an  incomplete  pedicle  valve.     (Productus  Icevi- 
costus  White.)     (W.  M.,  No.  6714.) 

Kinderhook,  bed  No.  7,  Burlington,  Iowa. 

13.  Direct  view  of  a  pedicle  valve.     (Productus  l&vicostus  White) 
(W.  M.,  No.  5924.) 

Chonopcctus   limestone,  Burlington,  Iowa. 

14-15.      Brachial    and    pedicle    views    of    an    incomplete    specimen 
preserving      both      valves.       (Productus      Icuvicostus      White) 
(W.  M.,  No.  296.) 

Lower  Burlington  limestone,  near  Springfield,  Missouri. 

Figs.  16-22.     PRODUCTUS  PARVUS  (Meek  and  Worthen) p.  121 

16-19.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  very 
perfect  shell.  (W.  M.,  No.  9915.) 

Chester  group,  Chester,  Illinois. 

20-22.     Posterior,    lateral    and    pedicle    views    of    another    perfect 
specimen.     (W.  M.,  No.  10923.) 
Pclla  beds,  Pella,  Iowa. 


38 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  I.    PLATE  XVI. 


"*m 


14 


15 


11 


16 


17  18 


19 


20 


21 


EXPLANATION  OF  PLATE  XVI. 

Figs.  1-15.     PRODUCTUS  OVATUS  Hall p.  132 

1-3.  Pedicle,  lateral  and  posterior  views  of  a  nearly  complete 
pedicle  valve.  (Productus  pileiformis.)  (W.  M.,  No.  14323.) 

Chester  group,  Chester,  Illinois. 

4-5.  Pedicle  and  lateral  views  of  a  pedicle  valve.  6-7.  Direct 
and  profile  views  of  the  external  impression  of  a  brachial  valve. 
(Productus  pileiformis.)  (W.  M.,  No.  14314.) 

Chester  group,  Meade  County,  Kentucky. 

8-9.  Pedicle  and  lateral  views  of  a  nearly  complete  pedicle 
valve.  (W.  M.,  No.  326.)  • 

Keokuk  limestone,  near  Springfield,  Missouri. 

10-11.  Pedicle  and  lateral  views  of  a  nearly  complete  pedicle 
valve.  (W.  M.,  No.  10130.) 

St.  Louis  limestone,  St.  Louis,  Missouri. 

12.  Direct  view  of  an  incomplete  pedicle  valve.     (Productus  Iccvi- 
costus  WhiteJ     (W.  M.,  No.  6714.) 

Kinderhook,  bed  No.  7,  Burlington,  Iowa. 

13.  Direct  view  of  a  pedicle  valve.     (Productus  l&vicostus  White) 
(W.  M.,  No.  5924.) 

Chonopectus   limestone,  Burlington,  Iowa. 

14-15.      Brachial    and    pedicle    views    of    an    incomplete    specimen 
preserving      both      valves.       (Productus      la-z'icostus      White) 
(W.  M.,  No.  296.) 

Lower  Burlington  limestone,  near  Springfield,  Missouri. 

Figs.  16-22.     PRODUCTUS  PARVUS   (Meek  and  Worthen) p.  121 

16-19.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  very 
perfect  shell.  (W.  M.,  No.  9915.) 

Chester  group,  Chester,  Illinois. 

20-22.     Posterior,    lateral    and    pedicle    views    of    another    perfect 
specimen.     (W.  M.,  No.  10923.) 
Pella  beds,  Pella,  Iowa. 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XVI. 


14 


, 


15 


13 


22 


16 


17  18 


19 


20  21 


EXPLANATION  OF  PLATE  XVII. 

Figs.  1-7.    ECHINOCONCHUS  ALTERNATUS  (Norwood  and  Pratten) p.  138 

1-4.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly  com- 
plete shell  without  the  surface  spines.  (W.  M.,  No.  14318.) 

Keokuk   limestone,   Warsaw,  Illinois. 

5.  View  of  the  interior  of  a  nearly  complete  brachial  valve. 
(W.  M.,  No.  14316.) 

Crawfordsville   shale,   Crawfordsvillc,  Indiana. 
6-7.     Lateral  and  pedicle  views  of  a  pedicle  valve  from  which  the 
spines  are  missing.     (W.  M.,  No.  14319.) 
Keokuk  limestone,  Warsaw,  Illinois. 

Figs.  8-9.    ECHINOCONCHUS   sp. 

Lateral  and  pedicle  views  of  a  large  and  nearly  complete  pedicle 
valve  lacking  the  spines.     (W.  M.,  No.  12988.) 
St.  Louis  limestone,  Carondelet,  Missouri. 

Figs.    10-15.     ECHINOCONCHUS   BISERIATUS    (Hall) p.  141 

10-13.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly 
perfect  specimen,  lacking  the  spines.  (W.  M.,  No.  14315.) 

Salem  limestone,  Spergen  Hill,  Indiana. 

14.  The  impression  of  the  external  surface  of  a  brachial  valve. 
15.  View  of  the  interior  of  a  brachial  valve.  (W.  M., 
No.  14766.) 

Salem   limestone,  Hull's  Hollow,  near  Alton,  Illinois. 


40 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XVII. 


EXPLANATION  OF  PLATE  XVIII. 

FigS.    1-6.      ECHINOCONCHUS    GENEVIEVENSIS    II.     sp p.    139 

1-2.     Pedicle  and  posterior  views  of  a  pedicle  valve.    3-4.     Pedicle 
and  lateral  views  of  another  specimen.     (W.  M.,  No.   14767.) 
Ste.  Genevieve  limestone,  2  mi.  N.  E.  Columbia,  Illinois. 
5.     The   impression  of   the  external   surface   of   a  brachial   valve. 
6.     View  of  a  small  pedicle  valve.     (W.  M.,  No.  14768.) 
Ste.  Genevieve  limestone,  Columbia,  Illinois. 

Figs.  7-10.     PRODUCTUS   INDIANENSIS  Hall p.  131 

7-8.  Views  of  two  brachial  valves,  natural  size.  9-10.  Pedicle 
and  lateral  views  of  the  specimen  illustrated  in  Fig.  7  (x  4). 
CW.  M.,  No.  14325.) 

Salem  limestone,  Spergen  Hill,  Indiana. 

Figs.  11-12.     PRODUCTUS  sp. 

External  and  internal  views  of  a  free  brachial  valve.  (W.  M., 
No.  7864.) 

Salem  limestone  (f),  Jersey  County,  Illinois. 

Figs.  13-15.     ECHINOCONCHUS  MORBILLIANUS    (Winchell) p.  142 

Pedicle,  lateral  and  posterior  views  of  the  holotype.  (U.  M., 
No.  2002.) 

Base  of  Burlington  limestone,  Burlington,  Iowa. 

Fig.  16.     PRODUCTUS   sp. 

One  of  the  specimens  associated  with  the  type  of  Echinoconchus 
morbillianus  by  Winchell,  but  clearly  not  a  member  of  the  same 
species.  (U.  M.,  No.  2003.) 

Chonopectus  limestone,  Burlington,  Iowa. 

Figs.  17-18.     STROPHALOSIA    KEOKUK    Beecher p.  145 

A   specimen  of    usual    size    attached    to    a    shell    of     Platyceras. 
18.     The  same    (x  4).     (W.  M.,  No.  13008.) 
Kcokuk   limestone,   Crawfordsville,  Indiana. 

Figs.  19-23.     STROPHALOSIA  SCINTILLA   Beecher '.p.  144 

19-20.     Specimens  of  usual  size  attached  to  the  shells  of  Product- 

ella     pyxidata.     (W.     M.,     No.     6701.)     21.     Another     similar 

specimen.      (W.    M.,    No.    13048.)      22.      An    enlargement    of 

Fig.  20  to  x  4.     23.     A  similar  enlargement  of  Fig.  21  to  x  4. 

Louisiana  limestone,  Louisiana,  Missouri. 


42 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XVIII. 


6 


13 


14 


15 


8 


11 


16 


12 


20 


17 


19 


21 


EXPLANATION  OF  PLATE  XIX. 

Figs.  1-21.     PRODUCTELLA  PYXIDATA  Hall p.  100 

1-14.  Pedicle  and  brachial  views  of  seven  nearly  perfect  shells. 
15.  View  of  the  interior  of  a  brachial  valve.  16-21.  Pedicle 
and  lateral  views  of  three  very  perfect  specimens.  (W.  M., 
No.  6696.) 

Louisiana   limestone,  Louisiana,  Missouri. 

Figs.  22-34.     PRODUCTELLA  CONCENTRICA    (Hall) p.    98 

22.  View  of  the  natural  mould  of  a  brachial  valve,  the  holotype. 
(A.  M.  N.  H.,  No.  5080-1.) 

Kindcrhook,  bed  No.  5,  Burlington,  Iowa. 

23-24.  Views  of  the  natural  moulds  of  two  brachial  valves,  en- 
tirely similar  to  the  holotype.  25-26.  Pedicle  and  lateral  views 
of  a  nearly  complete  pedicle  valve.  27-28.  Similar  views  of 
another  example.  (W.  M.,  No.  9821.) 

Choutcau  limestone,  Choutcau  Springs,  Missouri. 
29-31.     Pedicle,   brachial   and  lateral   views   of   a   nearly  complete 
specimen.     (W.  M.,   No.  6713.) 

Kinderhook,  Burlington,  Iowa. 

32-34.  Pedicle,  lateral  and  posterior  views  of  a  nearly  perfect  pedi- 
cle valve.  (W.  M.,  No.  14769.) 

Kinderhook,  bed  No.  6,  Burlington,  Iowa. 

Figs.  35-36.     STROPHALOSIA  CYMBULA  Hall  &  Clark p. 145 

Pedicle  and  brachial  views  of  a  nearly  complete  specimen,  the 
holotype.  (W.  M.,  No.  11897.) 

New  Providence  shale,  south  of  Louisville,  Ky. 

Figs.  37-38.     STROPHALOSIA   BEECHERI   Rowley p.  146 

Pedicle  and  brachial  views  of  a  nearly  perfect  pedicle  valve, 
filled  with  matrix,  but  showing  the  cardinal  area.  The  holo- 
type. (R.  R.  R.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  39-41.     PRODUCTELLA  NUMMULARIS    (Winchell) p.  101 

39.  View  of  the  exterior  of  a  brachial  valve.  40.  Internal  view 
of  a  brachial  valve.  41.  View  of  a  pedicle  valve.  Cotypes.  (U. 
M.,  No.  1340.) 

Chonopectus  sandstone,  Burlington,  Iowa. 


44 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XIX. 


3 


8 


9 


12 


23 


26 


13 


14 


15 


24 


27          28 


30  31 


34 


33 


v 


37 


4O 


41 


39 


38 


EXPLANATION  OF  PLATE  XX. 

Figs.    1-8.     RHIPIDOMELLA    MISSOURIENSIS    (Swallow) p.  148 

1-3.     Pedicle,  brachial  and  lateral  views  of  a  very  perfect  specimen. 
4-6.     Similar  views  of  another  specimen.    7.    Internal  view  of  a 
pedicle   valve,   showing   the   muscular   scar.     8.     Internal   view 
of   a  brachial  valve.      (W.   M.,   No.  6692.) 
Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  9-18,  30-35.     RHIPIDOMELLA  DIMINUTIVA  Rowley p.  153 

9-11.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete 
specimen.  (R.  R.  R.)  12-13.  Pedicle  and  brachial  views  of 
another  example.  14.  Internal  view  of  a  pedicle  valve.  15. 
Internal  view  of  a  brachial  valve.  (W.  M.,  No.  14222.) 

Burlington  white  chert,  Louisiana,  Missouri. 

16-18.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete 
specimen.  (W.  M.,  No.  8552.) 

Pier  son  limestone,  near  Springfield,  Missouri. 

30-32.  Pedicle,  brachial  and  lateral  views  of  a  very  perfect  speci- 
men, similar  in  size  to  the  type  specimen.  33-35.  Views  of  the 
same  specimen  enlarged  (x2).  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  19-21.    RHIPIDOMELLA  sp. 

Brachial,   lateral   and  pedicle   views  of   a   nearly   complete   but 
slightly  distorted  specimen.     (W.  M.,  No.  14220.) 

Fern  Glen  formation,  near  Kimmswick,  Missouri. 

Figs.  22-26.     RHIPIDOMELLA  DUBIA  (Hall) *. .  .p.  160 

22-24.  Pedicle,  brachial  and  lateral  views  of  a  very  perfect  ex- 
ample. 25-26.  Internal  views  of  two  pedicle  valves.  (W.  M., 
No.  13055.) 

Salcin  limestone,  Spcrgen  Hill,  Indiana. 

Figs.   27-29.     RHIPIDOMELLA   TENUICOSTATA   n.    sp p.  158 

27.  Pedicle  view  of  a  nearly  complete  specimen.  28.  Brachial 
view  of  another  specimen.  29.  Interior  view  of  a  brachial 
valve.  Cotypes.  (W.  M.,  No.  9673.) 

Chouteau   limestone,  Pettis  County,  Missouri. 

Figs.  36-43.     RHIPIDOMELLA  JERSEYENSIS  n.   sp .p.  157 

36-38.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete 
specimen.  39.  View  of  a  brachial  valve.  (W.  M.,  No.  7843.) 

Fern  Glen  formation,  near  Elsah,  Illinois. 

40.  Internal  view  of  a  pedicle  valve.  (W.  M.,  No.  4691.)  41.  In- 
ternal view  of  another  pedicle  valve.  42-43.  Internal  views  of 
two  brachial  valves.  (W.  M.,  No.  4692.) 

Fern  Glen  formation,  near  Kinnnswick,  Missouri. 


46 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XX. 


27 


I  *  * 

^      30       31 


21 


33         34        35 


42 


43 


36  37         38         39 


40 


41 


EXPLANATION  OF  PLATE  XXI. 

Figs.  1-4.     RHIPIDOMELLA  OWENI  Hall  &  Clarke. p.  151 

1-2.  External  and  internal  views  of  a  nearly  perfect  pedicle  valve. 
(W.  M.,  No.  4675.)  3-4.  External  and  internal  views  of  a 
nearly  complete  brachial  valve.  (W.  M.,  No.  7857.) 

New  Providence  shale,  Button  Mould  Knob,  Kentucky. 

Figs.    5-7.     RHIPIDOMELLA    BURLINGTONENSIS    (Hall) p.  149 

5.  View  of  a  nearly  perfect  pedicle  valve.     (W.  M.,  No.  11893.) 

Burlington  limestone,  Sagctown,  Illinois. 

6.  Similar  view  of  another  pedicle  valve.     (W.  M.,  No.  7858.) 

Burlington  limestone,  Burlington,  Iowa. 

7.  Pedicle  view  of  an  internal  cast,  a  little  restored  at  the  beak. 

(W.  M.,   No.  13045.) 

Chert  of  Burlington  limestone,  Pike  County,  Missouri. 

Figs.  8-27.     RHIPIDOMELLA  THIEMEI    (White) p.  155 

9-18.  External  and  internal  views  of  five  pedicle  valves.  19-24. 
External  and  internal  views  of  three  brachial  valves.  25-27. 
Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  speci- 
men. Cotypes.  (U.  M.,  No.  1348.) 

Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 

8.  View  of  a  nearly  perfect  pedicle  valve.     (W.  M.,  No.  6670.) 

Kinderhook,  Bed  No.  6,  Burlington,  Iowa. 

Figs.  28-32.    SCHIZOPHORIA  SEDALIENSIS  n.  sp p.  164 

28-31.     Pedicle,   brachial,   lateral   and   posterior  views  of   a  nearly 
perfect  specimen.     32.     View  of  the  interior  of  an  incomplete 
pedicle  valve,  showing  the  muscular  scar.     (W.  M.,  No.  14225.) 
Upper  Chouteau  limestone,  Sedalia,  Missouri. 

Figs.  33-34.     SCHIZOPHORIA  sp. 

33.     View  of  the  internal  cast  of  a  brachial  valve.    34.    View  of  an 
incomplete  internal  cast  of  a  pedicle  valve.    (U.  Ml,  No.  1351.) 
Chonopectus  sandstone,  Burlington,  Iowa. 


48 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXI. 


f  f  •  • 

11         13          15          17 


17          19 


10  12 


14 


16 


18          20 


21         22         23        24        25         26         27 


EXPLANATION  OF  PLATE  XXII. 

Figs.  1-6.     SCHIZOPHORIA  SWALLOVI    (Hall) p.  167 

1.  View  of  a  very  perfect  pedicle  valve.     (W.  M.,  No.  7916.) 

Burlington  limestone,  Springfield,  Missouri. 

2.  Similar  view  of  another  pedicle   valve.     3.     View   of   a   small 
brachial  valve.     (W.  M.,  No.  7861.) 

Burlington  limestone,  Henderson  County,  Illinois. 
4-5.    Brachial  and  posterior  views  of  a  nearly  complete  but  some- 
what crushed  example.     (W.  M.,  No.  7862.) 

Burlington   limestone,  Burlington,  Iowa. 
6.     View  of  internal  cast  of  a  pedicle  valve.     (W.  M.,  No.  14233.) 

Chert  of  Burlington  limestone,  Sedalia,  Missouri. 

Figs.  7-14.     SCHIZOPHORIA  POSTSTRIATULA  n.  sp p.  165 

7-11.  Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  a  very 
perfect,  but  somewhat  unsymmetrical  specimen.  Cotype.  (D. 
K.  G.,  No.  2701.) 

Fern  Glen  formation,  Fern  Glen,  Missouri. 

12-13.     Pedicle  and  posterior  views  of  a  nearly  complete  but  some- 
what crushed  example.     14.    View  of  the  interior  of  the  rostral 
portion  of  a  pedicle  valve.     Cotypes.     (W.  M.,  No.  4693.) 
Fern   Glen  formation,  near  Kinimswick,  Missouri. 

Figs.  15-17.     SCHIZOPHORIA  POSTSTRIATULA  n.  sp.  (?) p.  165 

Brachial,   pedicle    and   posterior   views   of    a    nearly    complete    but 
somewhat  crushed  specimen.     (W.  M.,  No.  8553.) 
Pierson   limestone,   near  Springfield,  Missouri. 


50 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXII. 


EXPLANATION   OF   PLATE  XXIII. 

Figs.  1-5.     SCHIZOPHORIA  SUBELLIPTICA   (White  &  Whitfield) p.  162 

1-2.    Views  of  two  pedicle  valves.     (W.  M.,  No.  14227.)     3.    View 
of  a  brachial  valve,  one  of  the  cotypes.     5.    View  of  a  large 
brachial  valve,  one  of  the  cotypes.    (U.  M.,  No.  1349.) 
Kindcrhook,  bed  No.  6,  Burlington,  Iowa. 

Figs.  6-19.     SCHIZOPHORIA  CHOUTEAUENSIS  n.  sp p.  163 

6-7.     Pedicle    and    brachial    views    of    a    nearly    perfect    specimen. 
8-11.    Brachial.  pedicle,  lateral  and  posterior  views  of   a  small 
but  very  perfect  example.     (W.  M.,  No.  14226.) 
Chontcau   limestone,  Providence,  Missouri. 

12-16.  Brachial.  pedicle,  lateral,  anterior  and  posterior  views  of  a 
nearly  perfect  specimen.  (W.  M.,  No.  9689.) 

Choutcau    limestone,   Pettis   County,   Missouri. 
17-19.    Brachial,   pedicle   and   posterior  views   of   a   nearly  perfect 
shell  with  much  more  depressed  pedicle  valve  than  usual.     It 
is  possible  that  this  specimen   should  not  be  referred  to  this 
species.     (W.  M.,  No.  8572.) 

Choutcau  limestone,  Green   County,  Missouri. 

Figs.  20-45.     CAMAROPHORIA  BISINUATA  (Rowley) p.  172 

20-24.  Pedicle,  brachial.  lateral,  anterior  and  posterior  views  of  a 
slightly  compressed  but  very  perfect  internal  cast.  25-29. 
Similar  views  of  another  very  perfect  internal  cast.  The  me- 
dian septum  is  shown  clearly  in  both  of  these  specimens,  that 
of  the  brachial  valve  less  clearly.  (W.  M.,  No.  9108.) 

Residual  chert,  Springfield,  Missouri. 

30-33,  34-37,  38-41.  Pedicle,  brachial,  lateral  and  anterior  views  of 
three  very  perfect  specimens,  metatypes.  Fig.  39  shows  clearly 
the  median  septum  of  the  brachial  valve  where  the  shell  has 
been  exfoliated.  (R.  R.  R.) 

Burlington   white   chert,  Louisiana,  Missouri. 

42-45.    Pedicle,  brachial,  lateral  and  anterior  views  of  a  very  per- 
fect specimen  referred  to  this  species.    (W.  M.,  No.  13929.) 
Kcokuk  limestone,  Warsaw,  Illinois. 

Figs.  46-51.     CAMAROPHORIA  EXPLANATA    (McChesney)    p.  173 

46-47.  Pedicle  and  brachial  views  of  a  sulphur  cast  of  the  holotype. 
(W.  M.,  No.  12424.) 

Chester   group,   Illinois. 

48-51.     Pedicle,  brachial,  lateral  and  anterior  views  of  a  very  per- 
fect specimen.     (W.  M.,  No.  7726.) 
Chester  group,  Chester,  Illinois. 

Figs.   52-60.    CAMAROPHORIA   HAMBURGENSIS  Weller p.  170 

52-55.  Brachial,  pedicle,  lateral  and  anterior  views  of  a  small  but 
nearly  perfect  specimen.  56-58.  Views  of  three  detached 
brachial  valves.  59-60.  Views  of  two  detached  pedicle  valves. 
(W.  M.,  No.  13937.) 

Hamburg   oolite    (Kindcrhook),  Hamburg,  Illinois. 


52 


ILLINOIS    STATE    GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  XXIII. 


11 


9 


10 


19 


17 


18 


15 


12 


13 


14 


16 


28        29 


»  I 


20       21       22 


23 


24        25       26      27 


>   • 


3O       31       32 


33 


34       35 


* 


36 


37 


42       43      44       45 


41 


38       39       4O 


46  47  48  49  5O  51  52  53 


^^^^  I- 


60          59 


58         57 


55 


I 


54 


EXPLANATION   OF   PLATE   XXIV. 

Figs.  1-8.    CAMAROTCECHIA  ELEGANTULA  Rowley p.  177 

Pedicle,  brachial,  lateral  and  anterior  views  of  two  nearly  perfect 
specimens.  Metatypes.  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  9-28.     CAMAROTCECHIA  TUTA   (Miller) p.  179 

9-16.  Pedicle,  brachial,  lateral  and  anterior  views  of  two  nearly 
perfect  specimens.  (D.  K.  G.,  No.  804.) 

Chouteau  limestone,  Scdalia,  Missouri. 

17-20.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly 
perfect  specimen.  (D.  K.  G.,  No.  1002.) 

Lake   Valley  Beds,  Sierra  County,  New  Mexico. 
21-24.     Pedicle,    brachial,    lateral   and   anterior   views   of    a   nearly 
complete    specimen.      (D.    K.    G.,    No.    902.)      25-28.     Similar 
views  of   another,   larger   specimen   probably   representing  the 
same  species.      (R.  R.   R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  29-33.    CAMAROTCECHIA  SUBGLOBOSA  n.  sp p.  180 

Pedicle,   brachial,   lateral,   posterior  and  anterior  views  of   a  very 
perfect  internal  cast.     Holotypes.     (D.  K.  G.,  No.  702.) 
Burlington  chert,  Newark,  Knox  County,  Missouri. 

Figs.  34-40.     CAMAROTCECHIA  CHOUTEAUENSIS  (Weller) p.  176 

34-37.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  very  per- 
fect specimen.  Cotypes.  (W.  M.,  No.  9704.) 

Chautcau   limestone,  Scdalia,   Missouri. 

38-40.  Pedicle,  lateral  and  anterior  views  of  a  smaller  example. 
Cotype.  (W.  M.,  No.  6709.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 

Figs.  41-60.    CAMAROTCECHIA   MUTATA    (Hall) p.  181 

41-48.  Pedicle,  brachial,  anterior  and  lateral  views  of  two  very 
large  individuals.  (W.  M.,  No.  7735.) 

Salem   limestone,  Spcrgcn  Hill,  Indiana. 

53-60.  Pedicle,  brachial,  lateral  and  anterior  views  of  three  nearly 
complete  specimens.  (W.  M.,  No.  13931.) 

Salem    limestone,  Hull's  Hollow,  near  Alton,  Illinois. 

Figs.  61-72.     CAMAROTCECHIA  GROSVENORI    (Hall) p.  183 

61-62.  Pedicle  and  brachial  views  of  a  small  specimen.  63.  An- 
terior view  of  a  larger  example.  64.  The  same  enlarged 
(x4).  (W.  M.,  No.  13932.) 

Salem    limestone,  Stincsville,  Indiana. 

65-68.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  large 
specimen.  69-72.  Similar  views  of  another  specimen.  (W. 
M.,  No.  13935.) 

Salem    limestone,   Bloomington,   Indiana. 

Figs.  73-81.     ALLORHYNCHUS  HETEROPSIS   (Winchell) p.  197 

73-76.  Brachial,  pedicle,  lateral  and  anterior  views  of  a  nearly  com- 
plete specimen.  77-79.  Pedicle,  brachial  and  lateral  views  of  a 
very  perfect  specimen.  80-81.  Pedicle  and  brachial  views  of  a 
third  specimen.  (Wl  M.,  No.  4756.) 

Kinderhook,  Bed  No.  4,  Burlington,  Iowa. 

55 


Fig.  82.     RHYNCHOPORA  PUSTULOSA  (White) p.  230 

View  of  a  large  pedicle  valve.     (W.  M.,  No.  4821.) 
Kinderhook,  Bed  No.  4,  Burlington,  Iowa. 

Figs.  83-86.     ALLORHYNCHUS  ACUTIPLICATUM  n.  sp p.  201 

Pedicle,  brachial,  lateral  and  anterior  views  of  a  very  perfect  speci- 
men.    Holotype.     (D.  K.  G.,  No.  2404.) 

Carterville  formation1'!).  Webb  City,  Alissonri. 


56 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXIV. 

'U* 


J 


..F       V 


9        10       11       12        13 


6 


•\W 
14 


15       16 


J   J 


17       is       19       20       21       22       23       24 


29       30      31       32      33 


25       26      27 


34       35       36      37 


m 


38 


4O       28 


41       42      43       44       45       46 


m 

47       48 


A 


W^ 


49       5O       51      52       53       54 


55 


56 
'  li 


57       58 


59      6O 


61       62     63 


64 


65       66 


o  a 

67      68       69       7O       71 


72 


73 


74       75 


76 


I 


77        78 


83 


84       85       86         SO        81          82 


EXPLANATION  OF  PLATE  XXV. 

Figs.  1-6.     ALLORHYNCHUS  MACRA   (Hall) p.  199 

1-2,  3-4.  Pedicle  and  brachial  views  of  two  examples  of  about  maxi- 
mum size.  (W.  M.,  No.  13936.) 

Salem  limestone,  Hull's  Hollow,  above  Alton,  Illinois. 
5-6.     Pedicle  and  brachial  views   (x4)   of  a  small  example  having 
the   characteristics   of    Rhynchonella   ricinula   Hall.      (W.    M., 
No.  2992.) 

Salem  limestone,  Stinesville,  Indiana. 

Figs.  7-17.     PUGNOIDES  OTTUMWA  (White) p.  193 

7-9.     Pedicle,  brachial  and  posterior  views  of  a  large  and  broad 
specimen.    10-11,  12-13.    Pedicle  and  brachial  views  of  two  very 
perfect  examples.     14-17.    Pedicle,  brachial,  anterior  and  poste- 
rior views  of  a  nearly  perfect  specimen.     (W.  M.,  No.  13930.) 
Ste.  Genevieve  limestone,  Fountain  Creek,  near  Waterloo, 
Illinois. 

Figs.  18-21.     RHYNCHOPORA   (?)    PERRYENSIS  n.  sp p.  239 

Pedicle,  brachial,  anterior  and  lateral  views  of  a  very  perfect  speci- 
men. (D.  K.  G.,  No.  2304.) 

Landing  76,  Perry  County,  Missouri. 

Figs.  22-26.     PUGNOIDES  BOONENSIS    (Shumard) p.  195 

Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  a  very 
perfect  specimen.  (D.  K.  G.,  No.  2201.) 

Burlington  limestone,  Louisiana,  Missouri. 

Figs.  27-33.     LIORHYNCHUS  GREENIANUM  (Ulrich) p.  185 

27-30.  Pedicle,  brachial,  anterior  and  lateral  views  of  a  very  perfect 
internal  cast.  31-33.  Brachial,  lateral  and  anterior  views  of 
another  specimen.  (W.  M.,  No.  13645.) 

Knobstone  shale,  New  Albany,  Indiana. 

Figs.  34-36.     PUGNAX  QUADRIROSTRIS  Beede p.  204 

Pedicle,  brachial  and  lateral  views  of  a  very  perfect  individual  (x4). 
(W.  M.,  No.  2996.) 

Salem  limestone,  Bloomington,  Indiana. 

Figs.  37-42.     PUGNAX  WORTHENI   (Hall) p.  203 

37-39.  Pedicle,  brachial  and  anterior  views  of  a  large  and  nearly 
perfect  specimen.  (W.  M.,  No.  13928.) 

Salem  limestone,  Hull's  Hollow,  above  Alton,  Illinois. 
40-42.    Similar  views  of  the  holotype.     (A.  M.  N.  H.,  No.  5064.) 
Salem  limestone,  near  Alton,  Illinois. 

Figs.  43-52.     SHUMARDELLA  MISSOURIENSIS  (Shumard) p.  222 

43-47.  Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  a 
nearly  perfect  specimen.  48-52.  Similar  views  of  another 
specimen.  (W.  M.,  No.  9667.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 


58 


MONOGRAPH  No.  1.    PLATE  XXV. 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


12  13  14 


5O 


51 


52 


EXPLANATION  OF  PLATE  XXVI. 

Figs.  1-9.     SHUMARDELLA  OBSOLENS  (Hall) p.  224 

1-3.  Brachial,  anterior  and  lateral  views  of  a  very  perfect  shell. 
4-6.  Pedicle,  posterior  and  anterior  views  of  another  specimen. 
7-9.  Brachial  and  two  lateral  views  of  three  separate  specimens. 
(W.  M.,  No.  9668.) 

Chouteau  limestone,  Chonteau  Springs,  Missouri. 

Figs.  10-14.     PARYPHORHYNCHUS  ELONGATUM  Weller p.  191 

Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a  very  per- 
fect specimen.  (D.  K.  G.,  No.  3901.) 

Kinderhook  limestone,  South  Fabius  River,  southeast  cor- 
ner of  Kno.r  County,  Missouri. 

Figs.  15-22.     PARYPHORHYNCHUS  STRIATICOSTATUM  (Meek  &  Worthen)  .p.  189 
15-19.    Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a 
nearly  perfect  specimen.     (W.  M.,  No.  10784.) 

Kinderhook  limestone,  Pike  County,  Illinois. 

20-22.  Pedicle,  brachial  and  lateral  views  of  another  nearly  perfect 
example.  (W.  M.,  No.  6658.) 

Kinderhook,  Bed  No.  4,  Burlington,  Iowa. 

Figs.  23-28.     PARYPHORHYNCHUS  TRANSVERSUM  Weller p.  188 

23.    View  of  a  nearly  perfect  pedicle  valve.     (W.  M.,  No.  10548.) 

Kinderhook  sandstone,  Kinderhook,  Illinois. 

24-28.    Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  a 
nearly  perfect  internal  cast.     (U.  M.,  No.  1375.) 
Chonopectus  sandstone,  Burlington,  Iowa. 


60 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXVI. 


8 


28 


EXPLANATION  OF  PLATE  XXVII. 

Figs.  1-6.     RHYNCHOTETRA  CAPUT-TESTUDINIS    (White) p.  206 

1-4.    Pedicle,  brachial,  lateral  and  anterior  views  of  the  holotype. 
(U.  M.,  No.  1376.) 

Base  of  Burlington  limestone,  Burlington,  Iowa. 
5.   View  of  an  incomplete  internal  cast  of  a  pedicle  valve.    6.   View 
of   an  incomplete  internal  cast  of  a  brachial  valve.      (U.   M., 
No.  1376.) 

Kinder  ho  ok,  Bed  No.  7,  Burlington,  Iowa. 

Figs.  7-15.     RHYNCHOTETRA  GIBBOSUM    (Greger) p.  211 

7-10.  Lateral,  pedicle,  brachial  and  anterior  views  of  a  very  perfect, 
small  specimen.  Cotype.  (D.  K.  G.,  No.  3602.) 

Burlington  limestone,  Hannibal,  Missouri. 

11-13.  Pedicle,  brachial  and  lateral  views  of  a  nearly  perfect,  large 
specimen.  Cotype.  (D.  K.  G.,  No.  3702.) 

Burlington  limestone,  Louisiana,  Missouri. 

14-15.   Views  of  two  imperfect  brachial  valves.     (VV.  M.,  No.  9715.) 
Burlington  limestone,  Marion  County,  Missouri. 

Figs.  16-20.     RHYNCHOTETRA  OVATUM    (Greger) p.  208 

16-17.  Pedicle  and  brachial  views  of  a  nearly  perfect  shell. 
18-20.  Pedicle,  brachial  and  lateral  views  of  another  specimen. 
Cotypes.  (D.  K.  G.,  No.  3802.) 

Chouteau    limestone,    Kicsenger    Bluff,    Warsaw,    Benton 
County,  Missouri. 


62 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXVII. 


16 


18 


19 


EXPLANATION  OF  PLATE  XXVIII. 

Figs.  1-8.     RHYNCHOTETRA  MISSOURIENSIS  n.  sp p.  210 

1-5.  Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
nearly  perfect  specimen.  (W.  M.,  No.  13962.)  6.  Anterior 
view  of  a  specimen.  (D.  K.  G.)  7-8.  Posterior  and  pedicle 
views  of  the  specimen  ground  for  the  cross-sections  of  the 
rostral  portion  of  the  shell.  (W.  M.,  No.  13965.) 
Burlington  limestone,  Missouri. 

Figs.  9-12.     RHYNCHOTETRA  ELONGATUM  n.  sp p.  209 

Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  perfect 
specimen,  the  holotype.  (W.  M.,  No.  8549.) 

Pierson  limestone,  near  Springfield,  Missouri. 

Figs.   13-24.     TETRACAMERA  SUBCUNEATA    (Hall) p.  214 

13-15.  Pedicle,  brachial  and  posterior  views  of  a  very  perfect  speci- 
men. 16-18.  Pedicle,  brachial  and  anterior  views  of  another 
specimen.  19.  Brachial  view  of  a  specimen  with  very  broad 
plications.  20.  Pedicle  view  of  a  specimen  with  very  concave 
postero-lateral  slopes.  21-22.  Brachial  and  lateral  views  of  a 
narrow,  elongated  specimen.  23-24.  Pedicle  and  lateral  views 
of  a  very  short  and  thick  specimen.  (W.  M.,  No.  7724.) 
Salem  limestone,  Salem,  Indiana. 

Figs.  25-34.     TETRACAMERA  ARCTIROSTRATA   (Swallow) p.  215 

25-29.  Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a 
very  perfect  specimen.  (D.  K.  G.,  No.  401.) 

Salem  limestone,  Boonville,  Missouri. 

30-34.    Similar  views  of  another  specimen.     (D.  K.  G.,  No.  501.) 
Salem  limestone,  Alton,  Illinois. 

Figs.  35-39.     TETRACAMERA  MISSOURIENSIS  n.  sp p.  216 

35-36.  Pedicle  and  lateral  views  of  the  internal  cast  of  a  pedicle 
valve.  37-38.  Brachial  and  lateral  views  of  the  internal  cast 
of  a  brachial  valve.  39.  View  of  the  internal  cast  of  a  brachial 
valve.  Cotypes.  (W.  M.,  No.  14280.) 

Residual  chert,  Callaway  County,  Missouri. 


64 


ILLINOIS    STATE   GEOLOGICAL   SURVEY.  MONOGRAPH  No.  1.    PLATE  XXVIII. 


.:> 


19  20 


22 


23  24 


25 


26 


27 


28 


29 


30 


31 


32 


33 


34 


35 


37 


39 


36        38 


EXPLANATION  OF  PLATE  XXIX. 

Figs.  1-13.     TETRACAMERA  SUBTRIGONA   (Meek  &  Worthen) p.  218 

1-5.    Pedicle,  brachial,   lateral,   posterior  and   anterior  views   of   a 
large  specimen.     6-10.    Pedicle,  lateral,  anterior,  posterior  and 
brachial  views  of  a  smaller  specimen.     (W.  M.,  No.  8683.) 
Keokuk  limestone,  Warsaiv,  Illinois. 

11.  View  of  an  internal  cast  of  a  pedicle  valve.     (W.  M.,  No.  8684.) 

Chert  of  Burlington  limestone,  Louisiana,  Missouri. 

12.  View  of  an  internal  cast  of  a  brachial  valve.     (W.  M.,  No.  320.) 

Residual  chert,  Springfield,  Missouri. 

13.  View  of  an  internal  cast  of  a  pedicle  valve  with  the  matrix 
broken  away  to  show  the  spondylium.     (W.  M.,  No.  13927.) 

Residual  chert,  Aurora,  Missouri. 

Figs.  14-18.     RHYNCHOPORA  PUSTULOSA   (White) p.  230 

Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a  very  per- 
fect specimen.  (W.  M.,  No.  9690.) 

Kinderhook,  Bed  No.  4,  Burlington,  Iowa. 

Figs.  19-30.     RHYNCHOPORA  HAMBURGENSIS  Weller p.  228 

19.  View  of  a  pedicle  valve.  20-21.  Views  of  two  brachial  valves. 
22.  Anterior  view  of  an  imperfect  specimen.  23-26.  Pedicle, 
brachial,  lateral  and  anterior  views  of  a  nearly  perfect  speci- 
men. 27-30.  Similar  views  of  a  smaller  specimen.  (W.  M., 
No.  7742.) 

Hamburg  oolite,  Kinderhook,  Hamburg,  Illinois. 

Figs.  31-38.     RHYNCHOPORA  BEECHERI  Greger p.  232 

31-32.    Pedicle  and  posterior  views  of  an  internal  cast.    33-34.    An- 
terior and  pedicle  views  of  an  internal  cast.     35-36.    Brachial 
and  pedicle  views  of  an  internal  cast.    37-38.    Brachial  and  ped- 
icle views  of  an  internal  cast.     (W.  M.,  No.  376.) 
Residual  chert,  Springfield,  Missouri. 


66 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXIX. 


11 


12 


13 


14 


15        16 


17 


18        19 


2O 


23       24     25      26      27      28     29 


30 


38         37 


36 


35 


34       33 


32 


EXPLANATION  OF  PLATE  XXX. 

Figs.  1-6.     RHYNCHOPORA  PERSINUATA    (Winchell) p.  233 

1.  View  of  an  internal  cast  of  a  pedicle  valve.  The  holotype. 
(U.  M.,  No.  1998.)  2.  Anterior  view  of  a  large  internal  cast, 
imperfect  posteriorly.  (W.  M.,  No.  6712.) 

Kinderhook,  Bed  No.  7 ,  Burlington,  Iowa. 

3-4.  Brachial  and  lateral  views  of  a  nearly  complete  specimen. 
5-6.  Pedicle  and  anterior  views  of  another  specimen.  (D.  K. 
G.,  No.  1302.) 

Lake  Valley  beds,  Lake  Valley,  New  Mexico. 

Figs.  7-15.     RHYNCHOPORA?  COOPERENSIS   (Shumard) p.  235 

7-11.  Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a 
nearly  complete  specimen.  (W.  M.,  No.  9661.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 
12-15.    Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  com- 
plete specimen.     (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  16-17.     RHYNCHOPORA  sp. 

16.  View  of  a  pedicle  valve.     (W.  M.,  No.  6716.) 

Burlington  limestone,  Burlington,  Iowa. 

17.  View  of  a  brachial  valve  probably  belonging  to  the  same  species. 
(W.  M.,  No.  13958.) 

Burlington  limestone,  Springfield,  Missouri. 

Figs.  18-21.     RHYNCHOPORA?  ROWLEYI  n.  sp p.  237 

Pedicle,  brachial,  anterior  and  lateral  views  of  a  very  perfect  speci- 
men. (R.  R.  R.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  22-25.     RHYNCHOPORA?  COOPERENSIS    (Shumard)    (?) p.  235 

Pedicle,  brachial,  posterior  and  lateral  views  of  a  somewhat  crushed 
specimen.  (W.  M.,  No.  8548.) 

Pierson  limestone,  near  Springfield,  Missouri. 

Figs.  26-29.     CENTRONELLA  LOUISIANENSIS  n.  sp p.  241 

26-27.  Pedicle  and  brachial  views  of  a  very  perfect  shell  (x4). 
28-29.  Pedicle  and  brachial  views  of  another  example  (x4). 
(W.  M.,  No.  6730.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  30-33.     TRIGERIA ?  CURRIEI   (Rowley) p.  245 

30-31.  Pedicle  and  brachial  views  of  a  very  perfect  shell  (x4). 
32-33.  Pedicle  and  brachial  views  of  another  specimen  (x4). 
(W.  M.,  No.  6732.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  34-39.     SELENELLA  PEDICULUS   (Rowley) p.  244 

34-35.    Pedicle  and  brachial  views  of  a  very  perfect  specimen  (x4). 
36-37.    Similar  views  of  another  specimen  (x4).    38-39.   Similar 
views  of  a  third  example  (x4).     (W.  M.,  No.  6731.) 
^Louisiana  limestone,  Louisiana,  Missouri. 

69 


Figs.  40-42.    CENTRONELLA   (  >  )  EMACIATA  Rowley p.  242 

Pedicle,  lateral  and  brachial  views  of  a  nearly  perfect  specimen,  the 
holotype.     (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  43-55.     DIELASMELLA  COMPRESSA  Weller p.  280 

43-44,  45-46,  47-48,  49-50.  Pedicle  and  brachial  views  of  four  differ- 
ent specimens.  51.  Pedicle  view  (x4)  of  specimen  figured  in 
Figs.  49-50.  52-53.  Pedicle  and  brachial  views  (x4)  of  speci- 
men figured  in  Figs.  45-46.  54-55.  Pedicle  and  brachial  views 
(x4)  of  specimen  figured  in  Figs.  47-48.  (W.  M.,  No.  11347.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 


70 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXX. 


w 

i 


IP 

d 


9 


10 


12          fa          14 


15 


16 


18 


19 


20 


24 


23 


26        27 


28       29       3O 


) 


11 


17 


25 


I 


31       32      33 


34         35 


36        37 


38      39 


54 


43 


44    45    46    47    48    49    5O 


40     41 


42         51 


52 


53 


55 


EXPLANATION  OF  PLATE  XXXI. 

FigS.    1-4.      DlELASMELLA   CALHQUNENSIS    n.    Sp p.   281 

1-3,  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  speci- 
men. 4.  View  of  a  partially  exfoliated  pedicle  valve.  (W.  M., 
No.  14246.) 

Hamburg  oolite,  Kinderhook,  Hamburg,  Illinois. 

Figs.  5-15.     CENTRONELLOIDEA  ROWLEYI   (Worthen) p.  247 

5-6.  Views  of  a  pedicle  and  a  brachial  valve,  the  cotypes.  (I.  S. 
M.)  7-10.  Pedicle,  brachial,  lateral  and  anterior  views  of  a 
nearly  perfect  specimen.  11-14.  Pedicle,  brachial,  lateral  and 
posterior  views  of  another  specimen.  15.  View  of  the  brach- 
idium.  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  16-18.     HAMBURGIA  TYPA  n.  sp p.  283 

16-17.  Views  of  two  pedicle  valves.  18.  View  of  a  brachial  valve. 
(W.  M.,  No.  14245.) 

Hamburg  oolite,  Kinderhook,  Hamburg,  Illinois. 

Figs.  19-24.     DIELASMOIDES  BISINUATA  Weller p.  254 

19-21.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  speci- 
men. 22-24.  Similar  views  of  a  larger  specimen.  (D.  K.  G., 
No.  1704.) 

Patrick's  Quarry,  Middle  Fabius  River,  Lewis  County,  Mis- 
souri. 

Figs.  25-27.     DIELASMA   SHUMARDANUM    (Miller) p.  268 

Lateral,  pedicle  and  brachial  views  of  a  nearly  perfect  specimen. 
(W.  M.,  No.  7770.) 

Chester  group,  Big  Hill,  Jackson  County,  Illinois. 

Figs.  28-34.     DIELASMA  SINUATA  n.  sp p.  262 

28-31.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly  com- 
plete internal  cast,  somewhat  restored  anteriorly.  32-33.  Views 
of  the  internal  casts  of  two  brachial  valves.  (W.  M.,  No.  334.) 

Residual  chert,  Springfield,  Missouri. 

34.    View  of  the  internal  cast  of  a  brachial  valve,  the  holotype  of 
Lingula  crawfordsvillensis  Gurley.     (W.  M.,  No.  6315.) 
Crawfordsville  shale,  Crawfordsville,  Indiana. 

Figs.  35-44.    DIELASMA  ARKANSANUM  n.  sp p.  269 

35-37.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  speci- 
men. 38-40.  Similar  views  of  a  smaller  example.  (D.  K.  G., 
No.  1505.) 

Webb  City,  Missouri    (Carterville  formation?). 
41-43.     Pedicle,   brachial   and   lateral   views   of    a   nearly    complete 
specimen.     44.     Pedicle    view   of    another    specimen.      Cotypes. 
(W.  M.,  No.  14255.) 

Fayetteville,  Arkansas. 

Figs.  45-49.     DIELASMA  BURLINGTONENSIS   (White) p.  261 

45-47.  Pedicle,  brachial  and  lateral  views  of  a  nearly  perfect  but 
slightly  distorted  specimen.  48-49.  External  and  internal  views 
of  a  pedicle  valve,  imperfect  anteriority.  Cotypes.  (U.  M., 
No.  1373.) 

Base  of  Burlington  limestone,  Burlington,  Iowa. 

72 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXI. 


•  I 


38  39  4O 


45  46  47  48  49 


EXPLANATION  OF  PLATE  XXXII. 

Figs.  1-17.     DIELASMA  CHOUTEAUENSIS  n.  sp p.  257 

1-4.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  large  specimen 
figured  by  Hall  and  Clarke  as  D.  formosa.  (W.  M.,  No.  12237.) 

Chouteau  limestone,  Missouri. 
5.   View  of  a  pedicle  valve.     (W.  M.,  No.  9703.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

6-8.  Pedicle,  brachial  and  anterior  views  of  a  nearly  perfect  speci- 
men. 9-12.  Posterior,  pedicle,  brachial  and  lateral  views  of  a 
nearly  perfect  specimen.  (W.  M.,  No.  9666.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 
13-15.    Pedicle,  brachial  and  lateral  views  of  an  imperfect  specimen. 
16-17.    Brachial  and  pedicle  views  of  another  imperfect  speci- 
men.    (W.  M.,  No.  8547.) 

Pierson  limestone,  near  Springfield,  Missouri. 

Figs.  18-28.     DIELASMA  INFLATA  n.  sp p.  264 

18-21.  Lateral,  brachial,  pedicle  and  anterior  views  of  a  very  perfect 
specimen,  the  holotype.  (W.  M.,  No.  14235.) 

Salem  limestone,  Barrett's  Station,  Missouri. 

22-24.   Lateral,  brachial  and  pedicle  views  of  a  very  perfect  but  nar- 
rower specimen.     (W.  M.,  No.  7772.)     25-28.    Lateral,  anterior, 
pedicle  and  brachial  views  of  a  specimen  which  probably  be- 
longs to  this  species.     (W.  M.,  No.  7773.) 
Salem  limestone,  Spergen  Hill,  Indiana. 


74 


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MONOGRAPH  No.  1.    PLATE  XXXII. 


27 


2O 


18 


EXPLANATION  OF  PLATE  XXXIII. 

Figs.   1-3.     DIELASMA  OSCEOLENSIS  n.  sp p.  260 

Pedicle,    brachial    and    lateral    views    of    the    holotype.      (W.    M., 
No.  7743.) 

Lower   Burlington    limestone,    Osccola,   Missouri. 

Figs.  4-5.     DIELASMA  FERNGLENENSIS  Weller p.  259 

Pedicle  and  brachial  views  of  the  holotype.     (W.  M.,  No.  4688.) 
Fern  Glen  formation,  near  Kimmswick,  Missouri. 

Figs.  6-11.     DIELASMA  SUBSPATULATUM  n.   sp p.  270 

Pedicle,    brachial   and   lateral   views   of   two    specimens.     Cotypes. 
(W.  M.,  No.  14254.) 

Washington  County,  Arkansas. 

Figs.  12-17.     DIELASMA  FORMOSUM  Hall p.  265 

12-14.     Pedicle,  brachial  and  lateral  views  of  the  holotype  of   D. 
obovata  H.  &  C.     (W.  M.,  No.  12238.) 
Salem  limestone  (?) ,  Kentucky. 

15-17.    Pedicle,  brachial  and  lateral  views  of  a  very  perfect  speci- 
men of  typical  form.     (W.  M.,  No.  449.) 
Salem  limestone,  Spergcn  Hill,  Indiana. 

Figs.  18-20.     DIELASMA  ILLINOISENSIS  n.  sp p.  267 

Pedicle,  brachial  and  lateral  views  of  the  holotype.    (W.  M.,  No. 
14770.) 

Chester  Group,  Paint  Creek  formation,  near  Modoc,  Ran- 
dolph County,  Illinois. 


76 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXIII. 


6 


15 


16 


17 


19  2O 


EXPLANATION  OF  PLATE  XXXIV. 

Figs.  1-24.     GIRTYELLA  iNDiANENSis    (Girty) p.  275 

1-9.  Pedicle,  brachial  and  lateral  views  of  three  nearly  perfect 
examples  from  the  typical  locality  of  the  species.  (W.  M., 
Nos.  7774  and  14237.) 

Pella  Beds,  Pella,  Iowa. 

10-11.  Pedicle  and  brachial  views  of  a  nearly  perfect  specimen. 
(W.  M.,  No.  14338.) 

Ste.  Genevieve  limestone,  near  Waterloo,  Illinois. 
12-17.   Pedicle,  brachial  and  lateral  views  of  two  very  perfect  speci- 
mens probably  belonging  to  this  species.     (D.  K.  G.,  No.  1603.) 
Webb  City,  Jasper  Co.,  Missouri.  (Carterville  -formation?) 
18-20.     Pedicle,   brachial   and   lateral   views    of   a    small    specimen. 
21-24.    Pedicle,  brachial,  lateral  and  anterior  views  of  another 
specimen.      (W.   M.,   No.   14800.) 

Lower   Chester   Group,  Rosiclare,  Illinois. 

Figs.  25-36.    GIRTYELLA  TURGIDA    (Hall) p.  273 

25-27.  Pedicle,  brachial  and  lateral  views  of  a  large  specimen. 
28-31.  Pedicle,  brachial  and  lateral  views  of  two  smaller  speci- 
mens. (W.  M.,  No.  14234.) 

Salem  limestone,  Blooinington,  Indiana. 

32-C3.  Brachial  and  lateral  views  of  a  very  convex  specimen. 
34-36.  Pedicle,  brachial  and  lateral  views  of  a  small  indi- 
vidual. (W.  M.,  No.  14771.) 

Salem  limestone,  Hull's  Hollow,  Madison  Co.,  Illinois. 

Figs.  37-41.    GIRTYELLA   BREVILOBATA    ( Swallow) p.  278 

37-39.  Pedicle,  brachial  and  lateral  views  of  a  very  perfect  speci- 
men. (W.  M.,  No.  7786.) 

Chester  Group,  Golconda,  Illinois. 

40-41.     Pedicle   and  brachial  views  of  an   internal  cast.    Holotype 
of  Dielasma  turgida  var.  elongata  Weller.    (W.  M.,  No.  4959.) 
Batcsville  sandstone,  Batcsville,  Arkansas. 

Figs.  42-47.    GIRTYELLA   INTERMEDIA  n.   sp p.  276 

42-44.  Pedicle,  brachial  and  lateral  views  of  a  very  complete  speci- 
men in  which  the  median  plication  in  the  brachial  valve  is 
well  developed.  45-47.  Smaller  views  of  another  example 
with  the  median  plication  of  the  brachial  valve  faintly  de- 
veloped. Cotypes.  (W.  M.,  No.  14772.) 

Paint   Creek   Formation,    near   Modoc,   Randolph    County, 
Illinois. 

Figs.  48-50.     GIRTYELLA  CEDARENSIS  n.  sp p.  272 

Pedicle,  brachial  and  lateral  views  of  an  internal  cast,  the  holo- 
type.  The  median  septum  is  clearly  shown  in  the  brachial 
view.  (D.  K.  G.,  No.  1402.) 

Northview  shale,  Cedar  Gap,  Wright  County,  Missouri. 

Fig.  51.     CRAN/ENA  (  ?)   ALLEI   (Winchell) p.  252 

View  of  the  holotype,  an  internal  cast  of  the  pedicle  valve.  (U. 
M.,  No.  2004.) 

Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 

79 


Figs.    52-54.      CRAX.-ENA    sp. 

Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  specimen. 
(W.  M.,  No.  9716.) 

Chouteau  limestone,  Pcttis  County,  Missouri. 

Figs.  55-59.    CRAN.ENA  SULCATA  n.  sp p.  251 

55-57.  Pedicle,  brachial  and  lateral  views  of  a  very  perfect  speci- 
men. 58-59.  Brachial  and  anterior  views  of  another  example. 
Cotypes.  (W.  M.,  No.  14250.) 

Salem   limestone,  Spcrgen   Hill,  Indiana. 

Figs.  60-66.     CRAN^NA  GLOBOSA  n.  sp p.  249 

Pedicle,  brachial  and  lateral  views  of  a  very  perfect  internal  cast. 
Holotype.  (W.  M.,  No.  14249.) 

Upper  Burlington  limestone,  Springfield,  Missouri. 
63-65.      Pedicle,   brachial    and   lateral   views  of    another    specimen. 
66.     View  of  the  interior  of  a  shell  showing  the  brachidium. 
(W.  M.,  No.   14248.) 

Burlington  white   chert,  Louisiana,  Missouri. 


80 


ILLINOIS    STATE    GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  XXXIV. 


123^ 


5      6 


7        89 


******** 


10       11 


12        13        14        15        16      17 


J  J  )  ,)  3 


18      19     2O     21     22      23     24 


25     26      27 


•  A 


28      29       3O      31       32       33       34      35      36 


mjj  ^a  s 


37      38     39      42      43      44      45      46      47 


^I^F       ^^       ^^  41 


48 


49  5O 


51 


4O 


*  *   i 


53        54      55        56        57       58 


6O          61         62 


63         64        65         66 


EXPLANATION   OF   PLATE  XXXV. 

Figs.   1-5.    ATRYPA   INFREQUENS  n.   sp p.  285 

1-2.  Pedicle  and  brachial  views  of  the  holotype.  3-5.  Pedicle, 
brachial  and  lateral  views  of  the  same  specimen  enlarged  x  2. 
(W.  M.,  No.  11348.) 

Glen  Park   limestone,  Glen  Park,  Missouri. 

Figs.  6-21.    CYRTINA  ACUTIROSTRIS    (Shumard) p.  286 

6-10.  Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a 
perfect  specimen.  11-15.  Similar  views  of  another  specimen. 
16-20.  Similar  views  of  a  third  example.  21.  View  of  the 
interior  of  a  pedicle  valve  showing  the  median  septum.  (W. 
M.,  No.  6691.) 

Louisiana   limestone,  Louisiana,  Missouri. 

Figs.   22-31.    CYRTINA   BURLINGTONENSIS   Rowley.... p.  288 

22-26.  Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of 
a  perfect  specimen.  (W.  M.,  No.  9676.) 

Choutcau    limestone,   Peltis   County,   Missouri. 
27-30.     Pedicle,   brachial,   lateral  and   anterior  views   of   the   holo- 
type.   (R.   R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

31.  View  of  an  internal  cast  of  a  pedicle  valve  showing  the 
median  septum  as  a  slit.  (R.  R.  R.) 

Burlington    chert,   Louisiana,  Missouri. 

Figs.  32-38.    CYRTINA  NEOCENES  Hall  and  Clarke p.  289 

32-36.     Pedicle,  brachial,   anterior,   posterior   and   lateral   views   of 
a  nearly  complete  internal  cast.     37-38.    Views  of  two  internal 
casts  of  pedicle  valves.      (W.   M.,   No.  5638.) 
Residual  chert,  Springfield,  Missouri. 

Figs.  39-40.     SPIRIFERINA  sp. 

Pedicle  and  brachial  views  of  a  somewhat  crushed  specimen.  (W. 
M.,  No.  7531.) 

Keokuk  limestone,  Keokuk,  Iowa. 

Figs.  41-49.     SPIRIFERINA   TRANSVERSA    (McChesney) p.  297 

41-44.     Pedicle,    brachial.    anterior   and  posterior  views   of   a  very 
perfect  specimen.     45-48.    Similar  views  of  another   example. 
49.    View  of  the  interior  of  a  pedicle  valve  showing  the  dental 
lamellae  and  median  septum.     (W.  M.,  No.  7507.) 
Chester  Group,  Chester,  Illinois. 

Figs.  50-58.     SPIRIFERINA  SPINOSA  (Norwood  and  Pratten) p.  299 

50-53.  Pedicle,  brachial,  anterior  and  posterior  views  of  a  nearly 
perfect  specimen.  (W.  M.,  No.  7496.) 

Chester   Group,  Randolph   County,  Illinois. 

54-58.  Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of 
another  specimen.  (W.  M.,  No.  7498.) 

Chester  Group,  Monroe  County,  Illinois. 


83 


Figs.  59-63.     SPIRIFERELLA   (?)   SCHUCHERTI   (Rowley) p.  416 

Pedicle,   brachial,   lateral,   posterior   and   anterior  views  of   a   very 
perfect  specimen.     Metatype.      (R.  R.  R.) 

Burlington   white   chert,  Louisiana,  Missouri. 

Figs.  64-72.    ACANTHOSPIRA   ACICULIFERA    (Rowley) p.  413 

64-67.    Pedicle,  brachial,  lateral  and  anterior  views  of  the  holotype. 
68-71.    Pedicle,   brachial,   lateral,   posterior   and   anterior   views 
of  the  same  specimen  enlarged  (x  4).     (R.  R.  R.) 
Louisiana   limestone,  Louisiana,  Missouri. 


84 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXV. 


J 


9 


11 


12 


13        14 


'6 


21 


16 


22 


23       24       25       26 


32 


27 


28        29       30 


31         34 


10 


15 


17        18        iQ        20 


33 


' 

"•IS 


35 


62         63 


68 


EXPLANATION   OF  PLATE  XXXVI. 

Figs.  1-5.     SPIRIFERINA  SALEMENSIS  n.  sp p.  296 

Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  the  holo- 
type.  (W.  M.,  No.  13948.) 

Salem   limestone,  Bloomington,  Indiana. 

Figs  6-7.    DELTHYRIS  CLARKSVILLENSIS    (Winchell) p.  301 

6.  View  of  a  pedicle  valve.  7.  Brachial  view  of  a  somewhat 
crushed  specimen.  (W.  M.,  No.  6699.) 

Louisiana    limestone,   Louisiana,   Missouri. 

Fig.  8.    DELTHYRIS  SUBORBICULARIS  Weller p.  303 

View  of  a  pedicle  valve,  the  holotype.     (W.  M.,  No.  11352.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 

Figs.  9-14.    DELTHYRIS  MISSOURIENSIS  Weller p.  302 

9.  View  of  a  pedicle  valve.  10.  View  of  a  brachial  valve.  (W. 
M.,  No.  14276.) 

Hamburg  oolite,  Calhoun  County,  Illinois. 

11-12.  Views  of  two  pedicle  valves.  13-14.  Views  of  two  brachial 
valves.  Cotypes.  (W.  M.,  No.  11351.) 

Glen  Park  limestone,  Glen  Park.  Missouri. 

Figs.  15-24.     DELTHYRIS  NOVAMEXICANA    (Miller) p.  304 

15-16.  Views  of  two  imperfect  pedicle  valves.  17.  Posterior  view 
of  an  incomplete  specimen.  Cotypes  of  S.  magnicostata  Weller. 
(W.  M.,  No.  4690.) 

Fern  Glen  formation,  near  Kimmswick,  Missouri. 
18-19.     Pedicle    and    posterior   views    of    an    incomplete    specimen. 
20-21.     Pedicle    and    brachial    views    of    a    smaller    incomplete 
specimen.     22-24.     Pedicle,   anterior  and  posterior  views   of  a 
third  specimen.     (D.  K.  G.) 

Lake  Valley  beds,  Lake  Valley,  New  Mexico. 

Figs.  25-34.    SPIRIFERINA  SOLIDIROSTRIS  White p.  292 

25.  View  of  a  pedicle  valve.  26-27.  Views  of  two  brachial  valves. 
28.  Brachial  view  of  a  somewhat  crushed  specimen.  Cotypes. 
(U.  M.,  No.  1372.) 

Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 

29.    View   of  the   interior  of   a  pedicle  valve   showing  the   median 
septum.     30.     View    of    a   pedicle   valve.     31-32.     Pedicle    and 
posterior  views  of  a  pedicle  valve.     33-34.    Views  of  two  im- 
perfect brachial  valves.     (W.  M.,  No.   13949.) 
Kinderhook,  Le   Grand,  Iowa. 

Figs.  35-40.    SPIRIFERINA   SUBTEXTA  White p.  291 

35-39.  Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of 
the  holotype.  (U.  M.,  No.  1701.) 

Burlington   limestone,  Burlington,  Iowa. 
40.    View  of  a  pedicle  valve.   (W.   M.,  No.  13914.) 

Fern  Glen  formation,  near  Kimmswick,  Missouri. 


87 


Figs.  41-48.    SPIRIFERINA   NORWOODANA    (Hall) p.  295 

41-44.  Posterior,  lateral,  brachial  and  pedicle  views  of  a  nearly 
perfect  specimen  (x  4).  45-48.  Pedicle,  brachial,  lateral  and 
anterior  views  of  a  nearly  perfect  specimen.  (x  4.)  (W. 
M.,  No.  5636.) 

Salem    limestone,   Blooiiiington,   Indiana. 

Figs.  49-53.    DELTHYRIS  SIMILIS  n.   sp p.  305 

Pedicle,  brachial,  anterior,  lateral  and  posterior  views  of  a  nearly 
perfect  internal  cast,  the  holotype.     ( D.  K.  G.,  No.  2903.) 
Residual  chert,  South  Branch,  Callaway  Co.,  Missouri. 

Figs.  54-57.     SPIRIFERINA  SUBELLIPTICA     (McChesney) p.  294 

54-55.  Pedicle  and  brachial  views  of  a  sulphur  cast  of  the  holo- 
type. (W.  M.,  No.  13239.) 

Button  Mould  Knob,  Kentucky. 

56.    View  of  a  pedicle  valve.     57.    View  of  the  interior  of  a  ped- 
icle valve  showing  the  median  septum.     (W.  M.,  No.   13427.) 
Lebanon,  Kentucky. 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXVI. 


6 


15 


18 


25 


3O 


35 


10 


16 


17 


19 


20         21 


22 


26 


27 


28 


29 


31 


32 


33 


34 


36         37 


38 


•M 

39 


45 


46 


48 


44 

> 

fl 


49 


5O 


51 


52 


11 


13        12 


23 


24 


40 


41         42 


43 

i 


53 


EXPLANATION  OF  PLATE  XXXVII. 

Figs.  1-7.    SPIRIFER  MARIONENSIS  Shumard p.  30.S 

1-5.  Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  a 
nearly  perfect  specimen.  (W.  M.,  No.  6700.) 

Louisiana   limestone,   Clarksvillc,   Missouri. 

6.  View  of  a  pedicle  valve  with  much  extended  hinge-line.  (W. 
M.,  No.  13335.)  7.  Brachial  view  of  a  specimen  with  very 
short  hinge-line.  (W.  M.,  No.  6694.) 

Louisiana    limestone,   Louisiana,   Missouri. 

Figs.  8-17.    SPIRIFER  VERNONENSIS  Swallow p.  310 

8-12.  Posterior,  pedicle,  brachial,  anterior  and  lateral  views  of  a 
very  perfect  specimen.  13.  View  of  a  large  pedicle  valve. 
(W.  M.,  No.  4686.) 

Fern  Glen  formation,  near  Kiminswick,  Missouri, 
14-17.    Pedicle,  brachial,   anterior  and  posterior  views  of  a  nearly 
perfect  specimen.     (W.  M.,  No.  13535.) 

Fern   Glen  formation,  Fern   Glen,  Missouri. 

Figs.   18-21.     SPIRIFER  OSAGENSIS    Swallow p.  314 

18-19.  Views  of  two  imperfect  pedicle  valves.  20.  View  of  a 
brachial  valve.  (W.  M.,  No.  13545.) 

Hannibal  sandstone,  Louisiana,  Missouri. 
21.    View  of  a  brachial  valve.     (W.  M.,  No.  5957.) 
Northvicw  sandstone,  Northview,  Missouri. 


90 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXVII. 


13 


EXPLANATION  OF  PLATE  XXXVIII. 

Figs.  1-5.     SPIRIFER  PIKENSIS  Rowley p.  312 

Pedicle,  brachial,  anterior,  posterior  and  lateral  views  of  the  holo- 
type.     (R.  R.  R.) 

Burlington  limestone,  Louisiana,  Missouri. 

Figs.  6-8.     SPIRIFER  SHEPARDI  n.  sp p.  313 

6-7.    Views  of  two  pedicle  valves.     8.    View  of   a  brachial  valve. 
Cotypes.     (W.  M.,  No.  8540.) 

Pierson  limestone,  near  Springfield,  Missouri. 

Figs.  9-13.     SPIRIFER  LATIOR  Swallow p.  316 

Lateral,  pedicle,  brachial,  anterior  and  posterior  views  of  a  nearly 
perfect  specimen.     (W.  M.,  No.  6707.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 


92 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XXXVIII. 


12 


13 


EXPLANATION  OF  PLATE  XXXIX. 

Figs.  1-10.     SPIRIFER  PLATYNOTUS  n.  sp p.  317 

1.   View  of  a  pedicle  valve.    2.   View  of  a  brachial  valve.     (W.  M., 
No.  6674.)     3-5.    Views  of  three  pedicle  valves.    6.    View  of  a 
brachial  valve.     Cotypes.     (W.  M.,  No.  13544.) 
Kinderhook,  Bed  No.  6,  Burlington,  Iowa. 

7-10.  Pedicle,  brachial,  anterior  and  lateral  views  of  a  nearly  per- 
fect specimen  probably  belonging  to  this  species.  (W.  M., 
No.  7502.) 

Kinderhook,  Bed  No,  5,  Burlington,  Iowa. 

Figs.  11-23.     SPIRIFER  MISSOURIENSIS   Swallow p.  319 

11-14.  Posterior,  lateral,  pedicle  and  brachial  views  of  a  nearly  per- 
fect example  showing  the  distinct  fasciculation  of  the  plications. 
(W.  M.,  No.  10719.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

15-18.  Pedicle,  brachial,  anterior  and  posterior  views  of  a  nearly 
perfect  specimen.  19-23.  Posterior,  lateral,  pedicle,  brachial 
and  anterior  views  of  a  large  specimen  somewhat  restored  at  the 
cardinal  extremities.  (W.  M.,  No.  9663.) 

Chouteau  limestone,  Chouteau  Springs,  Missouri. 

Figs.  24-26.     SPIRIFER  BIPLICATUS  Hall p.  320 

24-25.    Views  of  two  internal  casts  of  pedicle  valves.    26.    View  of 
the  internal  cast  of  a  brachial  valve.     (W.  M.,  No.  5931.) 
Chonopectus  sandstone,  Burlington,  lozva. 

Figs.  27-30.     SPIRIFER  BIPLICOIDES  n.  sp p.  323 

27.  View  of  a  plaster  cast  of  the  pedicle  valve  from  a  natural 
mould.  28.  View  of  the  internal  cast  of  a  brachial  valve. 
(W.  M.,  No.  6660.)  29.  View  of  a  plaster  cast  from  a  natural 
mould  of  the  pedicle  valve.  (W.  M.,  No.  14785.)  30.  View  of 
the  internal  cast  of  a  brachial  valve.  (W.  M.,  No.  14755.) 
Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 


94 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


A^ONOGRAPH  No.  1.    PLATE  XXXIX. 


11 


I  I  • 


23 


EXPLANATION  OF  PLATE  XL. 

Figs.  1-23.     SPIRIFER  LOUISTANENSIS   Rowley p.  322 

1-5.  Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a 
nearly  complete  specimen.  6-10.  Similar  views  of  another 
specimen.  11-13.  Brachial,  lateral  and  posterior  views  of 
another  specimen.  (W.  M.,  No.  5632.) 

Chouteau  limestone,  Green  County,  Missouri. 
14-15.    Views  of  two  pedicle  valves.     (W.  M.,  No.  14153.) 

Head  of  Middle  River,  Callaway  County,  Missouri. 
16-19.    Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  per- 
fect specimen.     20-23.    Pedicle,  brachial,   lateral   and   posterior 
views  of  a  nearly  perfect  specimen.    Metatypes.     (R.  R.  R.) 
Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  24-29.     SPIRIFER  LEGRANDENSIS  n.  sp p.  326 

24-28.  Pedicle,  brachial,  anterior,  lateral  and  posterior  views  of  a 
very  perfect  specimen.  29.  View  of  a  pedicle  valve.  Cotypes. 
(W.  M.,  No.  10720.) 

Kinderhook,  LeGrand,  Iowa. 

Figs.  30-34.     SPIRIFER  INSCULPTUS  Rowley p.  324 

Pedicle,  anterior,  posterior,  lateral  and  brachial  views  of  a  nearly 
perfect  specimen.  (W.  M.,  No.  13551.) 

Base  of  Burlington  limestone,  Fern  Glen,  Missouri. 


96 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XL. 


8 


10 


11 


16 


20 


12 


13 


21 


> 


-   : 


17          18 


19 


f 


22 


23 


14 


15 


25 


28 


27 


30 


29 


33 


34 


EXPLANATION  OF  PLATE  XLI. 

Figs.  1-5.     SPIRIFER  INSCULPTUS  Rowley p.  324 

Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of  the  holo- 
type.  (R.  R.  R.) 

Lower  Burlington  limestone,  Louisiana,  Missouri. 

Figs.  6-14.     SPIRIFER  INCERTUS  Hall p.  335 

6.  View  of  a  nearly  perfect  pedicle  valve.  (W.  M.,  No.  13529.) 
7-11.  Lateral,  pedicle,  brachial,  posterior  and  anterior  views  of 
a  nearly  perfect  specimen.  (W.  M.,  No.  8620.)  12-14.  Bra- 
chial, posterior  and  pedicle  views  of  the  holotype.  (A.  M. 
N.  H.,  No.  5111—1.) 

Burlington  limestone,  Burlington,  Iowa. 


98 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLI. 


r  t 


3 


12 


EXPLANATION  OF  PLATE  XLII. 

Figs.  1-3.     SPIRIFER  FORBESI  Norwood  and  Pratten p.  331 

Pedicle,  brachial  and  posterior  views  of  a  nearly  perfect  specimen 
probably  belonging  to  this  species.     (R.  R.  R.) 
Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  4-16.     SPIRIFER  TENUICOSTATUS   Hall p.  328 

4.  View  of  a  pedicle  valve.  5-9.  Pedicle,  brachial,  anterior,  poste- 
rior and  lateral  views  of  a  nearly  perfect  specimen.  Cotypes. 
(A.  M.  N.  H.,  No.  5121—1  &  2.) 

Warsaw  formation,  Dallas  and  Warsaw,  Illinois. 
10-13.    Pedicle,  brachial,  posterior  and  anterior  views  of  a  some- 
what distorted  specimen.     (W.  M.,  No.  7506.) 

Keokuk  limestone,  Bentonsport,  Iowa. 

14-16.  Lateral,  pedicle  and  brachial  views  of  a  somewhat  crushed 
specimen.  (W.  M.,  No.  7505.) 

Warsaiv  formation,  Warsaw,  Illinois. 

Figs.  17-21.     SPIRIFER  JEFFERSONENSIS  Weller p.  369 

17-18.  Pedicle  and  posterior  views  of  an  incomplete  pedicle  valve. 
19-21.  Views  of  three  brachial  valves.  Cotypes.  (W.  M.,  No. 
11350.) 

Glen  Park  limestone,  Glen  Park,  Missouri. 


100 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.- 1.    PLATE  jX 


4    m 

16 


EXPLANATION  OF  PLATE  XLIII. 

Figs.  1-10.     SPIRIFER  SUB^EQUALIS   Hall p.  327 

1-5.    Pedicle,  brachial,   posterior,  anterior  and   lateral  views   of   a 
nearly  perfect  specimen.     (D.  K.  G.,  No.  3501.) 

Webb  City,  Jasper  Co.,  Missouri. 

6-10.    Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
sulphur  cast  of  the  holotype.     (W.  M.,  No.  14773.) 
Warsaw  limestone,  Warsaw,  Illinois. 

Figs.  11-15.     SPIRIFER  LATERALIS  Hall p.  330 

Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of  the  holo- 
type.    (W.  M.,  No.  8619.) 

Clifton,  Madison  County,  Illinois. 

Fig.  16.     SPIRIFER  FORBESI   Norwood  and   Pratten p.  331 

View  of  a  pedicle  valve.     (W.  M.,  No.  13549.) 

Burlington  limestone,  Pettis  County,  Missouri. 

Fig.  17.     SPIRIFER   IMBREX    Hall p.  334 

View  of  a  brachial  valve,  the  holotype.     (A.  M.  N.  H.,  5110 — 1.) 
Burlington  limestone,  Burlington,  Iowa. 


102 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLIII. 


EXPLANATION  OF  PLATE  XLIV. 

Figs.  1-14.     SPIRIFER  WASHINGTONENSIS  n.  sp p.  339 

1-4.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly  com- 
plete specimen.  5-7.  Posterior,  pedicle  and  anterior  views  of 
another  specimen.  8-9.  Brachial  and  lateral  views  of  a  third 
specimen.  Cotypes.  (W.  M.,  No.  13550.) 

Keokuk  limestone,  Monroe  County,  Illinois. 

10-12.  Anterior,  pedicle  and  brachial  views  of  a  nearly  complete 
specimen.  Cotypes.  (W.  M.,  No.  7522.) 

Keokuk  limestone,  Spergen  Hill,  Indiana. 

13-14.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
Cotypes.  (W.  M.,  No.  13577.) 

Keokuk  limestone,  Salem,  Indiana. 

Figs.  15-19.     SPIRIFER  MUNDULUS  Rowley p.  333 

15-18.  Pedicle,  brachial,  posterior  and  anterior  views  of  a  very  per- 
fect shell.  Metatype.  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 
19.     View  of  an  incomplete  pedicle  valve.     (W.  M.,  No.  5635.) 
Burlington  limestone,  near  Springfield,  Missouri. 

Figs.  20-24.     SPIRIFER  BRECKENRIDGENSIS  n.  sp p.  342 

20-22.  Brachial,  lateral  and  anterior  views  of  a  very  perfect  speci- 
men. 23-24.  Pedicle  and  posterior  views  of  another  specimen. 
(D.  K.  G.,  No.  3302.) 

Chester  Group,  Breckenridge  County,  Kentucky. 


104 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLIV. 


?          iS^Bi^.     ••  i    \\ 

. 


24 


EXPLANATION  OF  PLATE  XLV. 

Figs.  1-31.     SPIRIFER  PELLAENSIS  n.  sp p.  340 

1-3.  Pedicle,  brachial  and  anterior  views  of  a  large  specimen. 
4-7.  Pedicle,  brachial,  posterior  and  anterior  views  of  another 
specimen. 

8-9.    Pedicle  and  brachial  views   of   a  very  large   specimen. 
10-11.   Brachial  and  anterior  views  of  a  nearly  perfect  specimen. 
12-14.    Brachial,  pedicle  and  lateral  views  of  a  nearly  perfect 
specimen.     (W.  M.,  No.  13571.) 

Pella  Beds,  Pella,  Iowa. 

15-16.    Posterior  and  anterior  views   of    a  specimen  with  a  short 
hinge-line.     (W.  M.) 
Pella  Beds,  Iowa. 

17-18.  Pedicle  and  brachial  views  of  a  nearly  perfect  specimen. 
19-21.  Lateral,  brachial  and  pedicle  views  of  a  nearly  perfect 
specimen.  (W.  M.,  No.  5771.) 

Pella  Beds,  Fort  Dodge,  Iowa. 

22-23.  Brachial  and  posterior  views  of  a  nearly  perfect  specimen, 
the  holotype.  24-25.  Posterior  and  lateral  views  of  another 
specimen.  (W.  M.,  No.  7535.) 

Pella  Beds,  Keosauqua,  Iowa. 

26-27.  Pedicle  and  brachial  views  of  a  nearly  perfect  specimen. 
28-29.  Pedicle  and  brachial  views  of  another  specimen.  (W.M., 
No.  7247.) 

Maxville  limestone,  Fayette  County,  Pennsylvania. 
30.    View  of  an  internal  cast  of  a  pedicle  valve.     31.    View  of  an 
internal  cast  of  a  brachial  valve.     (W.  M.,  No.  338.) 
Residual  chert,  Springfield,  Missouri. 


106 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLV. 


EXPLAXATIOX  OF  PLATE  XLYL 

Figs.  1-12.    SKUDFIX  IXTOEKSCEXS  Han 

1-5.  ffeflkfe.  bradnaL  latent,  posterior  and  anterior  views  of  a 
very  perfect  rprriwtn.  6-ft.  Pedicle.  hndnaL  posterior  and 
anterior  riem^  <of  anoKner  ^crinM&.  10-12.  Pedkle.  hfadnal 
«f  a  snaffler  speeinen.  (\V.  1L.  X«v  75B9.) 


/       .       -        -        '     /;.-.    .•- 


IMI.    SrvinK  cuotxAn-s  Rowfcy  .............................  p.  336 

LateraL  pedade.  ImciaaL  posterior  and  anterior  views  of  a  nearhr 
Mdatrpe.    CR.  R.  R.) 


• 


JLJJXOIS  STATE  GEOLOGICAL  Sewer, 


1,  PLATT  XLVL 


IT 


EXPLANATION  OF  PLATE  XLVII. 

Figs.  1-5.     SPIRIFER  CRAWFORDSVILLENSIS  n.  sp p.  338 

Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  the  holo- 
type.     (W.  M.,  No.  13528.) 

Crawfordsville  shale,  Crawfordsville,  Indiana. 

Figs.  6-16.     SPIRIFER  BIFURCUTUS  Hall p.  346 

6-8.    Pedicle,  posterior  and  lateral  views  of  a  nearly  complete  speci- 
men.   9-10.   Views  of  two  pedicle  valves.     (W.  M.,  No.  14784.) 

Salem  limestone,  Hull's  Hollow,  near  Alton,,  Illinois. 
11-14.     Pedicle,    brachial,    anterior    and    lateral    views    of    a   nearly 
perfect  specimen.     15-16.    Brachial  and  lateral  views  of  another 
specimen.     (W.  M.,  No.  7530.) 

Salem  limestone,  Spergen  Hill,  Indiana. 

Figs.  17-31.     SPIRIFER  LEIDYI  Norwood  and  Pratten p.  345 

17-19.  Pedicle,  brachial  and  anterior  views  of  a  very  perfect  speci- 
men. 20-22.  Brachial,  posterior  and  lateral  views  of  a  large 
specimen.  23-27.  Pedicle,  brachial,  anterior,  posterior  and  lat- 
eral views  of  a  perfect  specimen.  28-29.  Pedicle  and  brachial 
views  of  another  example.  30-31.  Lateral  and  brachial  views 
of  a  nearly  perfect  specimen.  (W.  M.,  No.  7511.) 
Chester  Group,  Chester,  Illinois. 


110 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLVII. 


3O 


EXPLANATION  OF  PLATE  XLVIII. 

Figs.  1-5.     SPIRIFER  TENUIMARGINATUS  Hall p.  355 

Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a  sulphur 
cast  of  the  holotype.     (W.  M.,  No.  14774.) 
Keokiik  limestone,   Warsaw,  Illinois. 

Figs.  6-16.     SPIRIFER  ROSTELLATUS  Hall p.  353 

6-10.    Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of  the 
holotype.     (W.  M.,  No.  6930.) 

Keokuk  limestone,   Warsaw,  Illinois. 

11-14.    Pedicle,  brachial,  anterior  and  lateral  views  of  an  internal 
cast  of  a  rather  broad  specimen.     (D.  K.  G.,  No.  3201.) 

Residual  chert,  Richland  Creek,  Callaway  Co.,  Missouri. 
15-16.    Pedicle  and   brachial   views  of   an   imperfect   internal  cast. 
(YY.  M.,  No.  339.) 

Residual  chert,  Springfield,  Missouri. 

Figs.  17-21.     SPIRIFER  STRIATIFORMIS  Meek p.  364 

17-20.    Pedicle,  brachial,  anterior  and  lateral  views  of  a  nearly  per- 
fect specimen.     (W.  M.,  No.  13578.) 

Waverly  Group,  Medina,  Ohio. 

21.    Mew  of  an  imperfect  pedicle  valve.     (W.  M.,  No.  5676.) 
Choutcan  limestone,  Green  County,  Missouri. 


112 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLVIII. 


EXPLANATION  OF  PLATE  XLIX. 

Figs.  1-14.     SPIRIFER  KEOKUK   Hall p.  350 

1-4.  Pedicle,  brachial,  anterior  and  lateral  views  of  a  nearly  com- 
plete specimen.  5-9.  Pedicle,  brachial,  lateral,  posterior  and 
anterior  views  of  another  specimen.  (W.  M.,  No.  13519.) 
10-14.  Posterior,  lateral,  brachial,  pedicle  and  anterior  views  of 
a  third  specimen.  (W.  M.,  No.  5626.) 
Keokuk  limestone,  Keokuk,  Iowa. 

Figs.  15-19.     SPIRIFER  FLOYDENSIS  n.  sp p.  351 

15-16.   Brachial  and  lateral  views  of  one  of  the  cotypes.     (W.  M. 
No.  13526.) 

Knobstone  formation,  Indiana. 

17-19.     Brachial,    anterior    and    lateral    views    of    another    cotype. 
(W.  M.,  No.  13525.) 

Knobstone  formation,  Floyd  County,  Indiana. 


114 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  XLIX. 


S'  \ 


18 


17 


EXPLANATION  OF  PLATE  L. 

Figs.  1-5.     SPIRIFER  LITTONI  Swallow p.  348 

Pedicle,  brachial,   lateral,   posterior  and  anterior  views  of  a  very 
perfect  specimen.     (W.  M.,  No.  14775.) 
St.  Louis  limestone,  Alton,  Illinois. 

Figs.  6-12.     SPIRIFER  INDIANENS'IS  n.  sp p.  352 

6-10.  Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
partially  restored  specimen.  11-12.  Views  of  two  pedicle  valves. 
Cotypes.  (W.  M.,  No.  7493.) 

Harrodsburg  limestone,  Spergen  Hill,  Indiana. 

Figs.  13-14.     SPIRIFER  MARSHALLENSIS  n.  sp p.  349 

Views  of  two  brachial  valves.     Cotypes.     (W.  M.,  No.  13541.) 
Kinderhook,  LeGrand,  Iowa. 

Figs.  15-22.     SPIRIFER  SUBROTUNDUS  n.  nom p.  356 

15-18.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  com- 
plete specimen.  (W.  M.,  No.  8618.)  19-22.  Pedicle,  brachial, 
lateral  and  anterior  views  of  another  specimen.  (W.  M., 
No.  5932.) 

Chonopectus  sandstone.  Burlington.  loi^a. 


116 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  L. 


3 


r-. 


13 


12 


EXPLANATION  OF  PLATE  LI. 

Figs.  1-2.     SPIRIFER  GRIMESI    Hall p.  361 

Pedicle  and  brachial  views  of  a  large  and  nearly  complete  speci- 
men.    (W.  M.,  No.  12942.) 

Burlington  limestone,  Springfield,  Missouri. 

Figs.  3-8.     SPIRIFER  MAPLENSIS  n.  sp p.  357 

3-6.    Views  of  four  different  pedicle  valves.     7-8.    Views   of   two 
brachial  valves.     (W.  M.,  No.  10580.) 

English  River  Grit,  Kinderhook,  Maple  Mill,  Washington 
County,  Iowa. 


118 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  LI. 


EXPLANATION  OF  PLATE  LII. 

Figs.  1-4.     SPIRIFER  GRIMESI  Hall p.  361 

1-3.  Anterior,  posterior  and  lateral  views  of  the  specimen  illus- 
trated on  Plate  LI,  Figs.  1  and  2.  (W.  M.,  No.  12942.)  4.  View 
of  a  pedicle  valve  in  the  usual  condition  of  preservation.  (\Y. 
M.,  No.  331.) 

Burlington  limestone,  Springfield,  Missouri. 

Figs.  5-11.     BRACK YTHYRIS  FERNGLENENSIS  Weller p.  372 

5.  Lateral  view  of  a  pedicle  valve.  6.  View  of  another  pedicle 
valve.  Cotypes.  (W.  M.,  No.  13538.)  7-11.  Pedicle,  brachial, 
lateral,  anterior  and  posterior  views  of  a  nearly  perfect  speci- 
men. (D.  K.  G.,  No.  3101.) 

Fern  Glen  formation,  Fern  Glen,  Missouri. 


120 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LII. 


EXPLANATION  OF  PLATE  LIII. 

Figs.  1-2.     SPIRIFER  GRIMES:  Hall p   3^ 

1.  Interior  view  of  a  pedicle  valve.  (W.  M.,  No.  10762.)  2.  View 
of  an  incomplete  pedicle  valve  with  the  plications  not  worn, 
showing  bifurcation.  (W.  M.,  No.  14786.) 

Burlington  limestone,  near  Springfield,  Missouri. 

Figs.  3-6.     SPIRIFER  ROWLEYI  n.  sp _   p    350 

3-4.  Pedicle  and  brachial  views  of  a  nearly  complete  specimen. 
5.  Lateral  view  of  another  example.  (W.  M.,  No.  14783.) 

Lake  Valley  Beds,  Lake  Valley,  New  Mexico. 
6.     View  of  a  worn  pedicle  valve.     (W.  M.,  No.  13919.) 
Fern  Glen  formation,  Fern  Glen,  Missouri. 

Fig.  7.     SPIRIFER  sp. 

Pedicle  view  of  a  nearly  complete  specimen.     (W.  M.,  No.  5653.) 
Keokuk  limestone,  near  Springfield,  Missouri. 

Figs.  8-9.     BRACHYTHYRIS  BURLINGTONENSIS  n.  sp p.  371 

8.  View  of  a  plaster  cast  from  a  natural  mould,  partially  restored. 
9.  View  of  the  natural  internal  cast  of  the  same  specimen. 
Cotypes.  (W.  M.,  No.  13543.) 

Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 


122 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LIII. 


EXPLANATION  OF  PLATE  LIV. 

Figs.  1-4.    SPIRIFER  ROWLEYI  n.  sp p.  360 

Pedicle,  brachial,  posterior  and  lateral  views  of  the  holotype. 
(W.  M.,  No.  13537.) 

Fern   Glen  formation,   Fern   Glcn3  Missouri. 

Figs.  5-10.    SPIRIFER  CALVINI  n.   sp p.  368 

5.    View  of  a  pedicle  valve.    Cotype.     (W.  M.,  No.  13542.) 

Kindcrhook,  Tauia  County,  Iowa. 

6-9.  Pedicle,  anterior,  posterior  and  lateral  views  of  a  nearly 
perfect  specimen.  10.  View  of  a  brachial  valve.  Cotypes. 
(\V.  M.,  No.  13540.) 

Kinderhook,  Lc  Grand,  Iowa. 


ILLINOIS    .STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LIV. 


EXPLANATION   OF   PLATE  LV. 

Figs.  1-8.    SPIRIFER  GREGERI  n.  sp • p.  359 

1-2.  Views  of  two  pedicle  valves  with  the  shell  partially  removed. 
3.  Posterior  view  of  another  specimen.  Cotypes.  (W.  M., 
No.  13552.) 

Summit  of  Choutcau  limestone,  Scdalia,  Missouri. 
4.    View  of  a  pedicle  valve  retaining  the  shell.     Cotype.     (W.  M., 
No.   13578.) 

Upper   Chouteau,   Head    of   Middle   River,   Callaway   Co., 

Missouri. 

5-8.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly 
complete  small  specimen.  (D.  K.  G.,  No.  3401.) 

Chouteau  limestone,  Newark,  Knox  County,  Missouri. 

Fig.  9.    SPIRIFER  MONTGOMERYENSIS  n.   sp p.  367 

View  of  a  pedicle  valve,  the  holotype.     (W.  M.,  No.  13330.) 
Kcokuk,  Crawfordsi'illc,  Indiana. 


126 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LV. 


EXPLANATION  OF  PLATE  LVI. 

Figs.  1-3.    SPIRIFER  LOGANI  Hall p.  363 

Pedicle,   brachial   and   anterior   views   of   a   nearly   complete   speci- 
men.    (W.  M.,  No.  6579.) 

Kcokitk   limestone,   Keokuk,  loii'a. 


128 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  LVI. 


EXPLANATION    OF    PLATE   LVII. 

Figs.    1-3.    SPIRIFER  LOGANI   Hall p.  363 

1-2.     Posterior   and  lateral    views   of   the    specimen   illustrated    on 
Plate  LVI.     3.    View  of  the  interior  of  the  pedicle  valve  of 
the   same   specimen.      (W.   M.,   No.  6579.) 
Kcokuk  limestone,  Keokuk,  Iowa. 

Figs.  4-11.    BRACHYTHYRIS  CHOUTEAUENSIS  Weller p.  373 

4-7.     Pedicle,    brachial,   posterior    and    lateral    views    of    a    nearly 
complete  specimen.     (W.  M.,  No.  8544.) 

Pierson    limestone,    near  Springfield,   Missouri. 
8-10.     Lateral,    pedicle    and    brachial    views    of    a   nearly    complete 
specimen.     Holotype.      (W.   M.,    No.  9664.) 

Chouteau  limestone,  Choutcau  Springs,  Missouri. 
11.     Brachial    view    of    a   somewhat    crushed    specimen.      (W.    M., 
No.  13536.) 

Fern   Glen  formation,  Fern   Glen,  Missouri. 

Fig.  12.    BRACHYTHYRIS  PECULIARIS   ( Shumard ) p.  381 

View  of  a  broad  pedicle  valve.     (W.  M.,  No.  9722.) 
Chouteau  limestone,  Pettis  County,  Missouri. 


130 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LVII. 


9 


10 


12 


11 


EXPLANATION   OF   PLATE   LVIII. 

Figs.   1-3.    SPIRIFER  MORTONANUS   Miller p.  366 

1-2.    Views  of  two  pedicle  valves.     (W.  M.,  No.  13328.)     3.    Pos- 
terior view  of  a  nearly  complete  specimen.    (W.  M..  No.  13521.) 
Crawfordsi'illc   Beds,   Crawfordsiillc,  Indiana. 

Figs.  4-8.    BRACHYTH YRIS  GURLEYI  n.  sp p.  377 

Pedicle,    brachial,    anterior,    posterior    and    lateral    views    of    the 
holotype.      (W.   M.,   No.    7550.) 
Salon  limestone,  Indiana. 

Figs.  9-20.     BRACK YTHYRIS  PECULIARIS   (Shumard) p.  381 

9-12.  Pedicle,  brachial,  anterior  and  lateral  views  of  a  very  per- 
fect specimen.  13-16.  Pedicle,  brachial,  posterior  and  lateral 
views  of  another  specimen.  (W.  M.,  No.  9662.) 

Chouteau    limestone,   Choutcau   Springs,  Missouri. 
17-20.    Pedicle,   brachial,   anterior   and    posterior    views   of   a  very 
narrow   specimen.      (W.   M.,   No.  7941.) 

Chouteau    limestone,   Pcttis    County,   Missouri. 


132 


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MONOGRAPH  No.  1.    PLATE  LVIII. 


20 


13 


14 


15 


16 


EXPLANATION  OF  PLATE  LIX. 

Figs.   1-6.    SPIRIFER   MORTONANUS   Miller p.  366 

1-3.  Pedicle,  brachial  and  lateral  views  of  a  nearly  perfect 
specimen.  (W.  M.,  No.  13328.)  4-6.  Pedicle,  posterior  and 
anterior  views  of  a  nearly  complete  specimen.  (W.  M.,  No. 
13321.) 

Crawfordsville  beds,  Crawfordsville,  Indiana. 

Figs.  7-14.    BRACHYTHYRIS  ALTONENSIS  n.  sp p.  379 

7-10.  Pedicle,  brachial,  anterior  and  posterior  views  of  a  very  per- 
fect internal  cast.  11-14.  Pedicle,  brachial,  lateral  and  an- 
terior views  of  another  specimen.  Cotypes.  (W.  M.,  No. 
10925.) 

St.  Louis  limestone,  i  mile  above  Alton,  Illinois. 

Figs.    15-19.    BRACHYTHYRIS    SEMIPLICATA    (Hall) p.  380 

Pedicle,  brachial,  anterior,  lateral  and  posterior  views  of  a  nearly 
perfect  specimen.  (W.  M.,  No.  14776.) 

Kinderhook,  3^/2   miles  N.   W.   of  Joncsboro,  Illinois. 


134 


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MONOGRAPH  No.  1.    PLATE  LIX. 


3 


.) 


8 


1O 


12 


14 


17 


18 


9 


11 


* 

13 


15 


16 


19 


EXPLANATION   OF   PLATE  LX. 

Figs.  1-15.    BRACHYTHYRIS  SUBCARDIIFORMIS  Hall p.  376 

1-3.  Pedicle,  lateral  and  brachial  views  of  a  sulphur  cast  of  the 
holotype.  (W.  M.,  No.  14213.) 

Salon   limestone,  above  Alton,  Illinois. 

4-6.  Pedicle,  lateral  and  brachial  views  of  a  large  specimen.  (W. 
M.,  No.  8617.) 

Edwardsville,  Indiana. 

7-11.  Pedicle,  brachial,  posterior,  lateral  and  anterior  views  of  a 
nearly  perfect  specimen.  (W.  M.,  No.  6352.)  12.  Posterior 
view  of  a  pedicle  valve  showing  the  raised  margins  of  the 
true  cardinal  area.  (W.  M.)  13-14.  Posterior  and  pedicle 
views  of  a  large  pedicle  valve.  15.  Anterior  view  of  another 
specimen.  (W.  M.,  No.  7520.) 

Salem  limestone,  Spcrgcn   Hill,  Indiana. 


136 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.    1.    PLATE  LX. 


EXPLANATION  OF  PLATE  LXI. 

Figs.   1-8.    BRACHYTHYRIS   SUBORBICULARIS   Hall p.  374 

1-2.    Pedicle  and  brachial  views  of  a  sulphur  cast  of  the  holotype. 
(W.  M.,   No.  14217.) 

Keokuk   limestone,   Kcokuk,   Iowa. 

3.    View  of  a  large  pedicle  valve.     (W.  M.,  No.  13409.)     4.    Ped- 
icle view  of  another  specimen.      (W.  M.,  No.  8627.) 

Keokuk   limestone,  Keokuk,  lozva. 

5.    View   of   a  brachial  valve.      (W.    M.,   No.  385.)      6.    View   of 
another  pedicle  valve.      (W.  M.,   No.  5655.) 

Burlington   limestone,   Springfield,   Missouri. 

7.    View  of  an  incomplete  brachial  valve.     8.    View  of  an  incom- 
plete pedicle  valve.     (W.  M.,  No.  13324.) 

Crawfcrdsrillc   beds,   Crawfordsville,   Indiana. 


138 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXI. 


a 


EXPLANATION  OF  PLATE  LXII. 

Figs.  1-12.    BRACHYTHYRIS   SUBORBICULARIS    (Hall) p.  374 

1-5.     Pedicle,   brachial,   posterior,   anterior   and   lateral  views   of   a 
nearly  complete  example.     (W.  M.,  No.  4721.) 

Burlington  limestone,  near  Sulphur  Springs,  Missouri. 
6-10.    Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
nearly  perfect  internal   cast.      (W.   M.,   No.  5652.) 
Residual  chert,  Springfield,  Missouri. 

11.  View  of  a  pedicle  valve.     (W.  M.,  No.   13324.) 

Crawfordsville   beds,   Crawfordsville,  Indiana. 

12.  View  of  a  small  pedicle  valve.     (W.  M.,  No.  13325.) 

Crawfordsz'ille    beds,    Offield    Creek,    near   Crawfordst'ille, 
Indiana. 


140 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXII. 


12 


EXPLANATION   OF   PLATE   LXIII. 

Figs.  1-4.     CYRTIA  INEXPECTANS  n.  sp p.  383 

1.  Posterior  view  showing  the  cardinal  area  with  covered  delthy- 
ris.  A  wax  impression  from  the  natural  mould  of  the  holo- 
type.  2-4.  Posterior,  pedicle  and  lateral  views  of  an  im- 
perfect internal  cast  of  a  pedicle  valve,  the  holotype.  (W. 
M.,  No.  381.) 

Residual  chert,  Springfield,  Missouri. 

Figs.  5-8,     SPIRIFERELLA    PLENA    (Hall) p.  412 

5-7.  Pedicle,  brachial  and  posterior  views  of  a  nearly  perfect 
specimen.  (W.  M.,  No.  7053.) 

Burlington   limestone,  Quincy,  Illinois. 

8.  View  of  the  interior  of  a  pedicle  valve   showing  the  strongly 

developed  dental   lamellae.      (W.   M.,   No.   7548.) 
Burlington   limestone,  Burlington,  Iowa. 

Figs.  9-10.    SPIRIFERELLA  LATIOR  n.  sp. p.  414 

9.  View   of   a  nearly   complete   pedicle   valve,   the   holotype.      (W. 

M.,   No.    13566.) 

Burlington   limestone,  Springfield,  Missouri. 

10.  View   of   the   interior   of   an   incomplete    pedicle    valve.      (W. 
M.,   No.   13570.) 

Burlington  limestone,  Osccola,  Missouri. 


142 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXIII. 


10 


EXPLANATION   OF    PLATE   LXIV. 

Figs.  1-4.    SPIRIFERELLA  PLENA   (Hall) p.  412 

1-2.     Anterior    and    lateral   views    of   the    nearly   perfect    specimen 
shown  on  Plate  LXIII,  Figs.  5-7.     (W.  M.,  No.  7053.) 

Burlington   limestone,  Quincy,  Illinois. 

3-4.     Posterior    and    pedicle    views   of    a    nearly    complete    internal 
cast.     (W.  M.,  No.  13554.) 

Residual  chert,  Sedalia,  Missouri. 

Figs.  5-9.    SPIRIFERELLA  NEGLECTA   (Hall) p.  415 

5-8.     Pedicle,   lateral,  brachial   and   anterior   views   of   a   small    hut 
nearly   complete   specimen.      (W.   M.,    No.   8616.) 

Kcokuk    limestone,   Edwardsville,   Indiana. 

9.    View  of  a  nearly  perfect  internal  cast  of  a  pedicle  valve,  show- 
ing the  elongate  dental  lamellae.      (W.  M..   No.  5650.) 
Residual   chert,   Springfield,   Missouri. 


144 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXIV. 


EXPLANATION  OF  PLATE  LXV. 

Figs.  1-4.     SPIRIFERELLA  NEGLECTA  (Hall) p.  415 

1-3.    Brachial,  pedicle  and  anterior  views  of  a  sulphur  cast  of  a 
nearly  perfect   specimen.      (W.   M.,   No.   14212.)      4.     Posterior 
view  of  a  nearly  perfect  specimen.     (W.  M.,  No.  13323.) 
Kcokuk  limestone,  Keoknk,  Iowa. 

Figs.  5-9.    PSEUDOSYRINX  MISSOURIENSIS  n.   sp p.  406 

Anterior,  posterior,  lateral,  pedicle  and  brachial  views  of  the  holo- 
type,  a  nearly  complete  specimen.     (W.  M.,  No.  13559.) 
Burlington  limestone,  Osceola,  Missouri. 


146 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXV. 


EXPLANATION  OF  PLATE  LXVI. 

FigS.    1-5.     PSEUDOSYRINX    GIGAS    n.    Sp p.   410 

Anterior,  posterior,  lateral,  pedicle  and  brachial  views  of  the  holo- 
type,  a  nearly  complete  specimen.     (W.  M.,  No.  12805.) 
Keokuk  (?) ,  Kentucky. 

Figs.  6-10.    PSEUDOSYRINX  KEOKUK  n.   sp p.  408 

Posterior,  anterior,  brachial,  pedicle  and  lateral  views  of  a  nearly 
complete  internal  cast.      (W.  M..   No.   5634.) 
Residual    chert,    Springfield,   Missouri. 

Figs.  11-13.    PSEUDOSYRINX   MISSOURIENSIS  n.  sp p.  406 

11.  View  of  the  cardinal  area  of  an  incomplete  pedicle  valve.  12. 
Lateral  view  of  an  incomplete  pedicle  valve.  (W.  M.,  No. 
13967.) 

Burlington    white   chert,   Louisiana,  Missouri. 

13.     View    of    the    cardinal    area    of    an    incomplete    pedicle    vn'.ve. 
(W.  M.,  No.  13559.) 

Burlington   limestone,  Osccola,  Missouri. 


148 


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MONOGRAPH  No.  1.    PLATE  LXVI. 


12 


EXPLANATION   OF   PLATE   LXVII. 

FigS.    1-9.      PSEUDOSYRINX    KEOKUK    n.    Sp p.   408 

1-5.    Posterior,   anterior,  lateral,   pedicle   and   brachial  views  of  a 
nearly  complete  internal  cast.    Cotype.     (W.  M.,  No.  13026.) 

Residual  chert. 

6-9.     Posterior,    anterior,    pedicle    and    lateral    views    of    a    nearly 
complete  specimen.     Cotype.     (W.  M.,  No.  13020.) 
Keokuk  limestone,   Warsaw,  Illinois. 

Fig.  10.     PSEUDOSYRINX  sp. 

View  of  the  cardinal  area  of  an  incomplete  pedicle  valve.      (\Y. 
M.,  No.  12807.) 

Crawfordsvillc   beds,   Crawfordsvillc,   Indiana. 

Figs.  11-13.    PSEUDOSYRINX  SAMPSONI  Weller p.  405 

11.    View  of  the  cardinal  area  of  an  incomplete   specimen  appar- 
ently belonging  to  this  species.     (W.  M.,  No.  12816.) 

Keokuk  limestone,   Warsaw,  Illinois. 

12-13.     Posterior   and    anterior    views    of    the    holotype.      (F.    A. 
Sampson.) 

Fern  Glen  formation,  Fern  Glen,  Missouri. 


150 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXVII. 


EXPLANATION   OF  PLATE  LXVIII. 

Figs.    1-7.     SYRINGOTHYRIS    HANNIBALENSIS    (Swallow) p.  388 

1-5.  Posterior,  anterior,  brachial,  pedicle  and  lateral  views  of  a 
very  perfect  exfoliated  specimen.  (W.  M.,  No.  1086.)  6-7. 
Interior  views  of  two  pedicle  valves  showing  the  syrinx. 
(W.  M.,  No.  13956.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  8-15.    SYRINGOTHYRIS  NEWARKENSIS  n.  sp p.  .594 

8-11.  Posterior,  anterior,  brachial  and  lateral  views  of  a  some- 
what restored  specimen.  12-15.  Lateral,  posterior,  anterior 
and  brachial  views  of  another  specimen.  Cotypes.  (D.  K. 
G.,  No.  3002.) 

Chouteau  limestone,  Newark,  Kno.r  County,  Missouri. 


152 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXVIII. 


15 


14 


EXPLANATION   OF   PLATE   LXIX. 

Figs.   1-5.    SYRINGOTHYRIS  TYPUS   Winchell p.  395 

Posterior,  lateral,  anterior,  brachial  and  pedicle  views  of  a  nearly 
complete  specimen.  (W.  M.,  No.  8630.) 

Burlington   limestone,  Pike   Comity,   Illinois. 

Figs.  6-9.     SYRINGOTHYRIS  TEXTUS    (Hall) p.  399 

6-7.  Anterior  and  brachial  views  of  a  rather  small  example.  8. 
Posterior  view  of  a  larger  specimen  showing  the  syrinx. 
9.  Lateral  view  of  another  large  specimen.  (W.  M.,  No. 
13959.) 

Knobstone  formation,  New  Albany,  Indiana. 


154 


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MONOGRAPH  No.  1.    PLATE  LXIX. 


m 


EXPLANATION  OF  PLATE  LXX. 

Figs.   1-4.    SYRINGOTHYRIS   TEXTUS    (Hall; p.  399 

Posterior,   anterior,    brachial   and   lateral    views   of   a   nearly   com- 
plete specimen.     (W.  M.,  No.  3275.) 

Knobstonc  formation,  New  Providence,  Indiana. 

Fig.  5.    SYRINGOTHYRIS  SOLIDIROSTRIS  n.  sp p.  403 

View   of   the   cardinal   area   and   the   interior   of  a   pedicle   valve, 
the   holotype.      (W.   M.,   No.   12814.) 
Kcokuk  limestone,  Kcokuk,  lou'a. 

Figs.  6-15.    SYRINGOTHYRIS  MISSOURI  Hall  and  Clarke p.  393 

6-9.    Anterior,   posterior,   brachial  and  lateral   views   of   the   holo- 
type.    (W.  M.,  No.  11954.) 

Choutcau   limestone,   Choutcau   Springs,  Missouri. 
10-13.    Anterior,  posterior,  brachial  and  pedicle  views  of  a  nearly 
complete    specimen.      14-15.     Posterior    and    lateral    views    of 
another  specimen.     (W.  M.,   No.  13957.) 

Chouteau  limestone,  Dogtown  Creek,  Calhoun  Co.,  Illinois. 


156 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXX. 


EXPLANATION    OF    PLATE   LXXI. 

Figs.   1-2.    SYRINGOTHYRIS   TEXTUS    (Hall) p.  399 

Anterior   and   posterior   views   of   a   nearly   complete   internal   cast. 
(W.  M.,  No.  7915.) 

Residual  chert,  Jasper  County,  Missouri. 

Figs.  3-7.    SYRINGOTHYRIS  SUBCUSPIDATUS   (Hall) p.  401 

Anterior,  brachial,  lateral,  posterior  and  pedicle  views  of  a  nearly 
perfect  specimen.      (W.  M.,  No.  8634.) 
Keoknk  limestone,   Warsaw,  Illinois. 

Figs.  8-9.     SYRINGOTHYRIS?  sp. 

8.    Posterior  view  of  a  nearly  complete  specimen.    9.   Anterior  view 
of  another  example.      (W.   M.,   No.   13964.) 
Hannibal   sandstone,    Louisiana,    Missouri. 


158 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXI. 


EXPLANATION  OF  PLATE  LXXII. 

Figs.  1-4.     SYRINGOTHYRIS  PLATYPLEURUS  n.  sp p.  397 

1-3.  Posterior,  anterior  and  lateral  views  of  a  nearly  complete 
internal  cast.  Holotype.  (W.  M.,  No.  13955.) 

Residual  chert,  Sedalia,  Missouri. 

4.  View  of  the  inner  surface  of  the  cardinal  area  of  a  pedicle  valve 
showing  the  delthyrial  plate  with  the  syrinx.  (W.  M., 
No.  7914.) 

Burlington  limestone,  Osceola,  Missouri. 

Figs.  5-12.     SYRINGOTHYRIS  EXTENUATUS    (Hall) p.  386 

5-6.  Posterior  and  pedicle  views  of  a  nearly  complete  pedicle  valve. 
7.  View  of  the  cardinal  area  of  another  specimen.  (W.  M., 
No.  13960.) 

Kinderhook,  Bed  No.  3,  Burlington,  Iowa. 

8-12.    Posterior,  anterior,  brachial,  pedicle  and  lateral  views  of  a 
nearly  complete  internal  cast.     (W.  M.,  No.  5929.) 
Chonopectus  sandstone,  Burlington,  lozua. 

Figs.  13-23.     SYRINGOTHYRIS  HALLI  W'inchell p.  390 

13-17.    Posterior,   anterior,   pedicle,   brachial   and   lateral   views   of 
one  of  Winchell's  cotypes.     (W.  M.,  No.  1369.) 
Kinderhook,  Bed  No.  4,  Burlington,  Iowa. 

18-22.  Posterior,  anterior,  pedicle,  brachial  and  lateral  views  of  a 
nearly  complete  specimen.  23.  View  of  a  very  perfect  brachial 
valve.  (W.  M.,  No.  4614.) 

Kinderhook,  Bed  No.  4,  Flint  River,  near  Burlington,  Iou<a. 


160 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXII. 


EXPLANATION  OF  PLATE  LXXIII. 

Figs.  1-5.     SYRINGOTHYRIS  CUSPIDATUS  Martin. 

Anterior,  pedicle,  posterior,  brachial  and  lateral  views  of  a  very 
perfect  specimen,  introduced  for  comparison  with  our  Ameri- 
can species.  (W.  M.,  No.  12519.) 

Carboniferous  limestone,  Waulsort,  Belgium. 

Figs.  6-7.     SYRINGOTHYRIS   (?)   sp. 

Posterior  and  lateral  views  of  a  nearly  complete  specimen.  (W.  M., 
No.  13961.) 

Chouteau  limestone,  Providence,  Missouri. 

Figs.  8-10.     SYRINGOTHYRIS  BUSHEERGENSIS  n.  sp p.  391 

8.  Posterior  view  of  an  incomplete  internal  cast  of  a  pedicle  valve. 
9.  Plaster  cast  from  a  natural  mould  showing  the  cardinal  area 
of  a  pedicle  valve.  10.  Internal  cast  of  an  incomplete  pedicle 
valve  showing  an  impression  of  the  syrinx.  (W.  M.,  No. 
13970.) 

Bushberg  sandstone,  near  Sulphur  Springs,  Missouri. 


162 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXIII. 


EXPLANATION  OF  PLATE  LXXIV. 

Figs.  1-11.     RETICULARIA  PSEUDOLINEATA    (Hall) p.  429 

1-5.  Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of  the 
holotype.  (W.  M.,  No.  7555.) 

Keokuk  limestone,  Warsaw,  Illinois. 

6-8.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete  speci- 
men. 9.  View  of  a  somewhat  crushed  pedicle  valve.  (W.  M., 
No.  13737.) 

Keokuk  limestone,  Keokuk,  Iowa. 

10-11.  Pedicle  and  brachial  views  of  a  nearly  complete  internal 
cast.  (D.  K.  G..  No.  2501.) 

Residual  chert,  South  Branch,  Callaway  County,  Missouri. 

Figs.  12-22.    RETICULARIA  SETIGERA  (Hall) p.  431 

12-16.    Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of 
a  very  perfect  specimen.     (W.  M.,  No.  7696.) 

Chester  Group,  Southern  Illinois. 

17.  View  of  the  internal  cast  of  a  pedicle  valve.  18.  View  of  the 
internal  cast  of  a  brachial  valve.  (W.  M.,  No.  13972.) 

Seneca  chert,  Seneca,  Missouri. 

19-22.  Pedicle,  brachial,  lateral  and  posterior  views  of  a  nearly 
complete  specimen.  (W.  M.,  No.  7632.) 

Chester  Group,  Monroe  County,  Illinois. 


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MONOGRAPH  No.  1.    PLATE  LXXIV. 


22 


EXPLANATION  OF  PLATE  LXXV. 

Figs.  1-10.     MARTINIA  CONTRACTA  (Meek  and  Worthen) p.  420 

1-4.    Pedicle,  brachial,  lateral  and  anterior  views  of  a  very  per- 
fect  specimen.     5-7.    Pedicle,   brachial   and   posterior   views   of 
another  specimen.     8-10.    Lateral,  brachial  and  anterior  views 
of  a  third  specimen.     (W.  M.,  No.  14777.) 
Chester  Group,  Red  Bud,  Illinois. 

Figs.  11-14.     MARTINIA  SULCATA  n.  sp p.  422 

11-13.  Pedicle,  brachial  and  anterior  views  of  a  nearly  complete 
specimen.  14.  Brachial  view  of  another  specimen.  Cotypes. 
(W.  M.,  No.  13677.)  ' 

Chester  Group,  Meade  County,  Kentucky. 

Figs.  15-19.     RETICULARIA  SALEMENSIS  n.  sp p.  433 

Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  the 
holotype.  (W.  M.,  No.  7558.) 

Salon  limestone,  Lanesi'ille,  Indiana. 

Fig.  20.     RETICULARIA  PSEUDOLINEATA    (Hall) p.  429 

Posterior    view    of    an    internal    cast    probably    belonging    to    this 
species.     (W.  M.,  No.  10764.) 

Residual  chert,  Springfield,  Missouri. 

Figs.  21-33.     RETICULARIA  COOPERENSIS    (Swallow) p.  428 

21-25.    Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  the 
holotype  of  R.  hirta  White  and  Whitfield.     (U.  M.,  No.  1367.) 

Kinder  ho  ok,  Bed  No.  7 ,  Burlington,  Iowa. 

26-30.    Anterior,  lateral,  pedicle,  brachial  and  posterior  views  of  a 
nearly   complete   specimen.     30-33.     Pedicle,   anterior   and   bra- 
chial views  of  another  specimen.     (W.  M.,  No.  9701.) 
Chouteau  limestone,  I'ettis  County,  Missouri. 


166 


ILLINOIS    STATE   GEOLOGICAL   SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXV. 


EXPLANATION  OF  PLATE  LXXVI. 

Figs.  1-3.     ACAMBONA  PRIMA  White p.  449 

Pedicle,  brachial  and  lateral  views  of  the  holotype.  (U.  M.,  No. 
1705.) 

Burlington  limestone,  Burlington,  Iowa. 

Figs.  4-6.     EUMETRIA   PERSTRIALIS    Rowley p.  441 

Pedicle,  brachial  and  lateral  views  of  the  holotype.     (R.  R.  R.) 
Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  7-11.     EUMETRIA  ALTIROSTRIS    (White) p.  438 

7-10.  Brachial,  lateral,  posterior  and  anterior  views  of  a  nearly 
complete  specimen.  11.  Brachial  view  of  another  specimen. 
(W.  M.,  No.  10575.) 

English  River  Gritstone,  Maple  Mill,  Washington  County, 
Iowa. 

Fig.  12.    EUMETRIA  OSAGENSIS   (Swallow) p.  439 

Brachial  view  of  an  imperfect  specimen.     (W.  M.,  No.  12387.) 
Chouteau  limestone,  Missouri. 

Figs.  13-17.     EUMETRIA  VERA    (Hall) p.  444 

Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a  nearly 
perfect  specimen.     (W.  M.,  No.  13575.) 
Chester  Group,  Chester,  Illinois. 

Figs.  18-24.     EUMETRIA  VERNEUILIANA  (Hall) p.  442 

18-21.  Brachial,  pedicle,  anterior  and  lateral  views  of  a  nearly  per- 
fect specimen.  22-24.  Pedicle,  brachial  and  lateral  views  of 
another  specimen.^  (W.  M.,  No.  7830.) 

Salem  limestone,  Spergen  Hill,  Indiana. 

Figs.  25-29.     EUMETRIA  COSTATA   (Hall) p.  445 

Pedicle,  lateral,  brachial,  anterior  and  posterior  views  of  a  nearly 
perfect  specimen.     (W.  M.,  No.  7833.) 
Chester  Group,  Chester,  Illinois. 

Figs.  30-34.    EUMETRIA  ACUTICOSTA  n.  sp p.  447 

Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  the  holo- 
type. (W.  M.,  No.  14778.) 

Chester  Group,  Johnson  County,  Illinois. 

Figs.  35-46.     PTYCHOSPIRA  SEXPLICATA  (White  and  Whitfield) p.  435 

35-39.  Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
nearly  perfect  specimen.  40-43.  Pedicle,  brachial,  lateral  and 
anterior  views  of  another  specimen.  (W.  M.,  No.  9688.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

44-46.  Pedicle,  brachial  and  anterior  views  of  a  metatype  of  Retzia 
raricosta  Rowley.  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  47-52.     HUSTEDIA  CIRCULARIS    (Miller) p.  451 

47-49.  Pedicle,  brachial  and  lateral  views  of  a  nearly  perfect  speci- 
men. (D.  K.  G.,  No.  1801.) 

Chouteau  limestone,  Sedalia,  Missouri. 

50-52.  Pedicle,  brachial  and  lateral  views  of  another  specimen. 
(W.  M.,  No.  9727.) 

Chouteau  limestone,  Pettis  County,  Missouri. 

168 


ILLINOIS    STATE   GEOLOGICAL   SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXVI. 


37  40  41  42 


*  +   *  * 


44         45        46  38  39  47         48        49        5O         51 


EXPLANATION  OF  PLATE  LXXVII. 

Figs.  1-20.     ATHYRIS  CRASSICARDINALIS  White p.  471 

1-2.  Exterior  and  interior  views  of  a  brachial  valve.  3-4.  Exterior 
and  interior  views  of  a  small  pedicle  valve.  Cotypes.  (U.  M., 
No.  1358.) 

Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 

5-6.  Exterior  and  interior  views  of  a  brachial  valve.  7.  Posterior 
view  of  a  shell  with  both  valves  in  articulation.  8-9.  Exterior 
and  interior  views  of  a  small  pedicle  valve.  10-11,  and 
12-13.  Exterior  and  interior  views  of  two  pedicle  valves. 
14-16.  Exterior  views  of  three  pedicle  valves.  17-18.  Exterior 
and  interior  views  of  a  brachial  valve.  19.  Exterior  view  of 
a  brachial  valve.  20.  Interior  view  of  a  brachial  valve.  (W. 
M.,  No.  9817.) 

Chouteau  limestone,  Sedalia,  Missouri. 

Figs.  21-25.     ATHYRIS  CRASSICARDINALIS  White    (??). 

21-23.  Pedicle,  brachial  and  lateral  views  of  a  nearly  complete 
pedicle  valve.  24-25.  Views  of  two  brachial  valves.  (W.  M., 
No.  6679.) 

Kinderhook,  Bed  No.  6,  Burlington,  Iowa. 

Figs.  26-31.     AMBOCOZLIA  LEVICULA   Rowley p.  426 

26-28.    Pedicle,  brachial  and  lateral  views  of  a  metatype.     29-31. 
Similar  views  of  the  same  specimen  enlarged  (x4).     (R.  R.  R.) 
Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  32-35.     AMBOCCELIA  PARVA  Weller p.  424 

32-33.    Views  of  two  pedicle  valves,  cotypes.    34-35.    Views  of  the 
same  specimens  enlarged   (x4).     (W.  M.,  No.  5952.) 
Northview  sandstone,  Northview,  Missouri. 

Figs.  36-43.    AMBOCCELIA  UNIONENSIS  n.  sp p.  425 

36-37.    Views   of  two   pedicle  valves.     38-39.    Views   of   the   same 
specimens    enlarged     (x4).      40.     View    of    a    brachial    valve. 
41.    View  of  the  same  specimen  enlarged   (x4).     42-43.    Views 
of  two  large  pedicle  valves.     Cotypes.     (W.  M.,  No.  14782.) 
Kinderhook,  Zl/2  miles  northwest  of  Jonesboro,  Illinois. 

Figs.  44-54.     AMBOCCELIA   MINUTA   White p.  423 

44-47.     Pedicle,    brachial,    lateral   and   posterior    views    of    a   large 

specimen   (x4).     48-50.    Pedicle,  brachial  and  lateral  views  of 

another  specimen    (x4).     51-54.    Pedicle,  brachial,  lateral  and 

posterior  views  of  a  third  specimen  (x4).     (W.  M.,  No.  6719.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  55-59.     COMPOSITA  (?)  CORPULENTA  (Winchell) p.  495 

Pedicle,  brachial,  lateral,  anterior  and  posterior  views  of  a  nearly 
complete  specimen.  (W.  M.,  No.  13899.) 

Chonopectus  sandstone,  Burlington,  Iowa. 


171 


Figs.  60-69.     ATHYRIS  DENSA  Hall  and  Clarke p.  469 

60-63.  Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  com- 
plete specimen.  64-65.  Exterior  and  interior  views  of  a  nearly 
perfect  pedicle  valve.  66-67.  Exterior  and  interior  views  of 
another  pedicle  valve.  Cotypes.  (W.  M.,  No.  12364.) 

Salem  limestone,  Colesburgh,  Kentucky. 

68-69.  External  and  internal  views  of  a  pedicle  valve,  the  holotype 
of  Centronella  crassicardinalis  White.  (A.  M.  N.  H.,  No. 
5067—1.) 

Salem  limestone,  Spergen  Hill,  Indiana. 


172 


ILLINOIS    STATE   GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXVII. 


4  5 


1O  11 


12  13  14  15  16 


6789 

"   ^|  •< 

17  18 


19 


2O 


26         27       28 


21  22  23 


33 


24  25 


* 


35 


36  37  34 


31  3O  29 


42  43 


>    J 

42 

w          '  ,      ( "S 


38 


40 


44  45  46  47 


48 


39 


49  5O  51  52  53 


54 


55 


56 


57 


58 


59 


60 


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^* 


63 


68 


64 


65 


66 


67 


69 


EXPLANATION  OF  PLATE  LXXVIII. 

Figs.  1-5.     ATHYRIS   LAMELLOSA    (Leveille) p.  465 

1.  Pedicle  view  of  a  nearly  complete  specimen.     (W.  M.,  No.  7605.) 

Keokuk  limestone,  Warsaw,  Illinois. 

2.  Pedicle  view  of  a  nearly  complete  internal  cast.     (W.  M.,  No. 

14224.) 

Residual  chert,  Cooper  County,  Missouri. 

3-4.  Pedicle  and  posterior  views  of  a  nearly  complete  internal  cast. 
(W.  M.,  No.  7599.) 

Burlington  chert,  Louisiana,  Missouri. 

Figs.  6-9.     ATHYRIS  PAPILIONIFORMIS  McChesney p.  468 

Pedicle,  brachial,  lateral  and  posterior  views  of  a  sulphur  cast  of 
the  holotype.  (W.  M.,  No.  13232.) 

Chester  Group,  Fountain  Bluff,  Illinois. 

Figs.  10-14.    ATHYRIS  HANNIBALENSIS  (Swallow) p.  467 

10-12.  Lateral,  brachial  and  anterior  views  of  a  nearly  complete 
specimen.  13-14.  Pedicle  and  posterior  views  of  another  speci- 
men. (W.  M.,  No.  6690.) 

Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  15-20.     ATHYRIS  LAMELLOSA  (Leveille) p.  465 

15-16.  Views  of  two  pedicle  valves  upon  one  of  which  the  lamellar 
extensions  of  the  shell  are  well  preserved.  (W.  M.,  No.  13539.) 

Fern  Glen  formation,  Fern  Glen,  Missouri. 

17-20.  Brachial,  pedicle,  lateral  and  anterior  views  of  an  exfoliated 
specimen.  (W.  M.,  No.  8545.) 

Pierson  limestone,  near  Springfield,  Missouri. 

Figs.  21-24.     CLIOTHYRIDINA  GLENPARKENSIS  n.  sp p.  473 

21-22.  Pedicle  and  lateral  views  of  a  nearly  complete  specimen. 
23-24.  Brachial  and  posterior  views  of  another  specimen.  (W. 
M.,  No.  13901.) 

Fern  Glen  -formation,  Fern  Glen,  Missouri. 

Fig.  25.     CLIOTHYRIDINA  PARVIROSTRA    (Meek  and  Worthen) p.  481 

View  of  the  internal  cast  of  a  pedicle  valve.     (W.  M.,  No.  383.) 
Residual  chert,  Springfield,  Missouri. 


174 


ILLINOIS    STATE   GEOLOGICAL   SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXVIII. 


EXPLANATION  OF  PLATE  LXXIX. 

Figs.  1-11.     CLIOTHYRIDINA  OBMAXIMA  (McChesney) p.  475 

1.   View  of  a  large  pedicle  valve.     (W.  M.,  No.  7592.) 
Fern  Glen  formation,  Monroe  County,  Illinois. 

2-6.    Pedicle,  brachial,   anterior,  posterior  and  lateral   views   of   a 
nearly  perfect  specimen!     (W.  M.,  No.  13917.) 
Fern  Glen  formation,  Chautauqua,  Illinois. 

7-11.    Pedicle,  brachial,  anterior,  lateral  and  posterior  views  of   a 
nearly  perfect  specimen.     (W.  M.,  No.  7596.) 
Keokuk  limestone,  Keokuk,  Iowa. 

Fig.  12.     CLIOTHYRIDINA  INCRASSATA    (Hall) p.  4/7 

View  of  a  pedicle  valve.     (W.  M.,  No.  342.) 

Burlington  limestone,  Springfield,  Missouri. 

Figs.  13-16.     CLIOTHYRIDINA  PROUTI    (Swallow) p.  474 

Pedicle,   brachial,   anterior  and   lateral   views   of    a   nearly   perfect 
specimen.     (W.  M.,  No.  46951.) 

Fern  Glen  formation,  near  Kimmswick,  Missouri. 


176 


ILLINOIS    STATE    GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXIX. 


15 


EXPLANATION  OF  PLATE  LXXX. 

Figs.  1-12.     CLIOTHYRIDINA  TENUILINEATA    (Rowley) p.  478 

1-3,  4-6.  Pedicle,  brachial  and  lateral  views  of  two  specimens.  (U. 
M.,  No.  1358.) 

Kinderhook,  Bed  No.  6,  Burlington,  Iowa. 

7-9,  10-12.  Pedicle,  brachial  and  lateral  views  of  two  specimens, 
metatypes.  (R.  R.  R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  13-24.     CLIOTHYRIDINA  HIRSUTA    (Hall) p.  479 

13-15,  16-18.  Pedicle,  brachial  and  lateral  views  of  two  specimens. 
(W.  M.,  No.  13920.) 

Salem  limestone,  Hull's  Hollow,  Madison  County,  Illinois. 
19-21,  22-24.    Pedicle,  brachial  and  lateral  views  of  two  specimens. 
(W.  M.,  No.  1369.) 

Salem  limestone,  near  Boonville,  Missouri. 

Figs.  25-30.     CLIOTHYRIDINA  LENTICULARIS  n.  sp p.  480 

25-27,  28-30.  Pedicle,  brachial  and  lateral  views  of  two  specimens. 
(W.  M.,  No.  12992.)  . 

St.  Louis  limestone,  near  Carondelet,  Missouri. 

Figs.  31-60.     CLIOTHYRIDINA  SUBLAMELLOSA  (Hall) p.  482 

31-33,  34-36.  Pedicle,  brachial  and  lateral  views  of  two  young  speci- 
mens having  the  form  and  size  of  C.  hirsuta.  (W.  M., 
No.  7628.) 

Chester  Group,  Chester,  Illinois. 

37-39,  40-42,  43-45.  Pedicle,  brachial  and  lateral  views  of  three 
young  specimens  having  the  general  character  of  C.  hirsuta. 
(W.  M.,  No.  13921.) 

Lower  Chester,  Fairview  Point,  Hardin  Co.,  Illinois. 
46-48.    Pedicle,   brachial   and   lateral   views   of   an  undistorted   but 
somewhat  exfoliated  specimen.    49-50.   Pedicle  and  lateral  views 
of  another  specimen.     (W.  M.,  No.  7613.) 

Chester  Group,  Chester,  Illinois. 

51-53,  54-56.  Pedicle,  brachial  and  lateral  views  of  two  specimens 
partially  preserving  the  surface  spines.  (W.  M.,  No.  7628.) 

Chester  Group,  Chester,  Illinois. 

57-58.  Brachial  views  of  two  different  specimens.  59-60.  Pedicle 
views  of  two  other  specimens.  (W.  M.,  No.  14781.) 

Lower  Chester,  Fairview  Point,  Hardin  Co.,  Illinois. 

Figs.  61-66.     CLIOTHYRIDINA  PARVIROSTRA   (Meek  &  Worthen) p.  481 

61-63.  Pedicle,  lateral  and  brachial  views  of  a  slightly  crushed 
specimen.  (W.  M.,  No.  7611.) 

Keokuk  limestone,  Jersey  County,  Illinois. 

64-66.  Brachial,  lateral  and  pedicle  views  of  a  nearly  complete 
specimen.  (W.  M.,  No.  7614.) 

Keokuk  limestone,  Warsaw,  Illinois. 


178 


ILLINOIS    STATE   GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXX. 


•  *  J 


1  2345  6  13  14  15 


J 


7  8  9  1O  11  12 


16  17  18 


19  2O  21  22  23  24  25  26  27 


31       32     33     34       35      36      28        29     3O 


>  I 


37  38  39  4O  41  42  43  44  45 


46 


47 


48 


49 


5O 


51 


52 


53          57 


58 


54 


55 


56 


59 


6O 


61  62  63  64  65  66 


EXPLANATION   OF   PLATE  LXXXI. 

Figs.  1-15.    COMPOSITA  SUBQUADRATA    (Hall) p.  489 

1-4.  Pedicle,  brachial,  posterior  and  lateral  views  of  a  nearly 
perfect  specimen.  5-8.  Anterior,  pedicle,  brachial  and  pos- 
terior views  of  another  specimen.  (W.  M.,  No.  7627.) 

Chester  Group,  Chester,  Illinois. 

9-11.     Pedicle,    anterior    and    lateral   views    of    a    nearly    complete 
specimen.      12-15.     Brachial,    lateral,    anterior    and    posterior 
views  of  a  nearly  complete  specimen.     (W.  M.,  No.  13926.) 
Chester  Group,  Chester,  Illinois. 

Figs.   16-45.    COMPOSITA   TRINUCLEA    (Hall) p.  486 

16-20.  Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
very  perfect  specimen.  21-24.  Pedicle,  brachial,  anterior  and 
posterior  views  of  another  specimen.  25-26.  Pedicle  and 
brachial  views  of  a  third  specimen.  (W.  M.,  No.  7620.)  27-30. 
Pedicle,  brachial,  lateral  and  anterior  views  of  a  nearly  per- 
fect specimen.  (W.  M.,  No.  389.) 

Salem    limestone,    Spcrgcn    Hill,    Indiana. 

31-34.  Lateral,  pedicle,  brachial  and  anterior  views  of  a  nearly 
perfect,  large  example.  (W.  M.,  No.  13926.) 

Salem  limestone,  Hull's  Hollow,  Madison  County,  Illinois. 
35-36.    Pedicle   and  lateral  views  of   a  very  narrow  and  elongate 
example.     37-38.    Brachial  and  anterior  views  of  an  old  shell. 
39-42.    Pedicle,  lateral,  anterior  and  posterior  views  of  a  nearly 
perfect    specimen.      43.     Brachial    view    of    a    nearly    perfect 
specimen.      44-45.     Anterior    and    posterior    views    of    another 
specimen.      (W.   M.,    No.  7617.) 
Pclla  Beds,  Pella,  Iowa. 

Figs.  46-51.    COMPOSITA  LEWISENSIS  n.  sp p.  488 

46-48.  Pedicle,  brachial  and  posterior  views  of  a  nearly  perfect 
specimen.  49-51.  Pedicle,  lateral  and  anterior  views  of  an- 
other specimen.  Cotypes.  (D.  K.  G.,  No.  203.) 

Patrick  Quarry,  Middle  Fabius  River,  Lewis  County,  Mis- 
souri. 

Figs.   52-57.    COMPOSITA   PENTAGONIA   n.    sp p.  492 

52-54.  Posterior,  lateral  and  pedicle  views  of  a  very  perfect 
internal  cast.  55-57.  Anterior,  lateral  and  brachial  views  of 
another  example.  Cotypes.  (D.  K.  G.,  No.  102.) 

Residual  chert,  South  Branch,  Callaway  County,  Missouri. 


\  80 


ILLINOIS    STATE   GEOLOGICAL    SURVEY. 


MONOGRAPH  No.  1.    PLATE  LXXXI. 


10 


11 


12 


13 


^^^m^^r 


16        17      18       19         2O         14  15 


21          22 


23 


'9^^ 


24 


25  26 


48 


27        28      29 


30 


» 


52         53 


54 


35 


46      47 


W   ll  f 


36 


44         45          41 


42          38 


EXPLANATION  OF  PLATE  LXXXII. 

Figs.  1-10.   COMPOSITA  SULCATA  n.  sp p.  490 

1-5.  Pedicle,  brachial,  lateral,  posterior  and  anterior  views  of  a 
nearly  complete  specimen.  6-10.  Anterior,  posterior,  brachial, 
lateral  and  pedicle  views  of  a  smaller  example.  Cotypes. 
(W.  M.,  No.  13782.) 

Chester   Group,  Mcadc   County,  Kentucky. 

Figs.  11-13.    COMPOSITA  OPPOSITA  (White  and  Whitfield) p.  494 

Pedicle,  brachial  and  lateral  views  of  the  holotype.  (A.  M.  N.  H., 
No.  5000-1.) 

Upper  Kinderhook,  Burlington,  Iowa. 

Figs.  14-20.     COMPOSITA  L^VIS  n.  sp p.  491 

14-17.     Pedicle,  brachial,  lateral  and  posterior  views  of  a  very  per- 
fect specimen.     18-20.     Pedicle,  brachial  and  anterior  views  of 
another  specimen.    Cotypes.     (D.  K.  G.,  No.  303.) 
Chester  Group,  Breckinridgc  Co.,  Kentucky. 

Figs.  21-26.     COMPOSITA  GLOBOSA  n.  sp p.  493 

21-23.  Pedicle,  lateral  and  anterior  views  of  a  nearly  perfect  speci- 
men. 24-26.  Brachial,  posterior  and  anterior  views  of  another 
specimen.  Cotypes.  (W.  M.,  No.  3003.) 

Keokuk  limestone,  near  Springfield,  Missouri. 

Figs.  27-38.    NUCLEOSPIRA  BARRISI  White  p.  455 

27-31.  Pedicle,  brachial,  posterior,  anterior  and  lateral  views  of  a 
nearly  complete  specimen.  32-33.  Exterior  and  interior  views 
of  a  pedicle  valve.  34-35.  Exterior  and  interior  views  of  an- 
other pedicle  valve.  36.  View  of  a  pedicle  valve.  37.  View  of 
a  brachial  valve.  38.  Interior  view  of  an  imperfect  brachial 
valve.  Cotypes.  (U.  M.,  No.  1360.) 

Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 

Figs.  39-42.     NUCLEOSPIRA  OBESA  Rowley p.  457 

39-41.  Pedicle,  brachial  and  lateral  views  of  a  metatype.  42. 
Brachial  view  of  the  same  specimen  enlarged  (x3).  (R.  R. 

R.) 

Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  43-48.     NUCLEOSPIRA  ROWLEYI  n.  sp p.  454 

43-44,  45-46,  47-48.     Pedicle  and  brachial  views  of  three  different 
individuals,  enlarged  (x  4).     Cotypes.     (W.  M.,  No.  6733. 
Louisiana  limestone,  Louisiana,  Missouri. 

Figs.  49-60.     NUCLEOSPIRA  MINIMA  Weller p.  456 

49-54.     Views  of  six  separate  valves.     55-60.     Views  of  the  same 
valves  enlarged    (x4).     Cotypes.     (W.  M.,   No.   11349.) 
Glen  Park  limestone,  Glen  Park,  Missouri. 

Figs.  61-63.     CAMAROPHORELLA  LENTICULARIS  (White  and  Whitfield)  ..  .p.  459 
61.     View  of  an  internal  cast  of  a  pedicle  valve.    62-63.     Views  of 
two  internal  casts  of  brachial  valves.    Cotypes.     (U.  M.,  No.  1356.) 
Kinderhook,  Bed  No.  5,  Burlington,  Iowa. 

183 


Figs.  64-69.     ROWLEYELLA  FABULITUS    (Rowley) p.  463 

64.  Pedicle  view  of  a  nearly  complete  specimen  from  which  the 
shell  is  partially  removed,  showing  the  median  septum.  The 
spiral  brachidium  is  clearly  shown  in  this  specimen,  but  does  not 
appear  in  the  photograph.  65-66.  Pedicle  and  brachial  views  of 
the  same  specimen  enlarged  (x4).  67.  Pedicle  view  of  a  smaller 
specimen  from  which  the  shell  has  been  removed  on  each  side. 
68-69.  Pedicle  and  brachial  views  of  the  same  specimen  (x4) 
showing  the  median  septum  in  each  valve.  (W.  M.,  No.  14279.) 
Burlington  white  chert,  Louisiana,  Missouri. 

Figs.  70-79.     CAMAROPHORELLA    MTSSOURIENSIS    (Winchell) p.  460 

70-73.  Pedicle,  brachial,  lateral  and  anterior  views  of  the  holotype. 
(U.  M.,  No.  1993.)  74-76,  77-79.  Pedicle,  brachial  and  lateral 
views  of  two  specimens,  metatypes  of  Seminula  buckleyi  Row- 
ley. (R.  R.  R.) 

Louisiana   limestone,  Louisiana,  Missouri. 


184 


ILLINOIS    STATE   GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXXII. 


11    12   13 


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8         9         10 


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28       29       30     31 


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32      34 


36      37        33      35       38 

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43     44     45      46     47    48 


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39   40   41      42 


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49     51     53 


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56 


57 


61      62       63 


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58       5O     54     52 


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66       67      7O 


71       72 


73 


74 


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76         77  78         79 


EXPLANATION  OF  PLATE  LXXXIII. 

Figs.  1-2.     SPIRIFER  FORBESI  Norwood  and  Pratten p.  331 

Views  of  two  separate  brachial  valves.  (W.  M.,  Nos.  5654  and 
13531.) 

Burlington   limestone,  Springfield,  Missouri,  and  Burling- 
ton, Iowa. 

Figs.  3-5.     BRACHYTHYRIS  PECULIARIS  (Shumard) p.  381 

Pedicle,  brachial  and  lateral  views  of  a  very  perfect  specimen. 
(W.  M.,  No.  14780.) 

Chouteau  limestone,  Calhoun  County,  Illinois. 

Fig.  6.     BRACHYTHYRIS  BURLINGTONENSIS   n.    sp p.  371 

Brachial  view  of  an  internal  cast.     (W.  M.,  No.  7501.) 
Kinder  hook,  Bed  No.  5,  Burlington,  Iowa. 

Figs.  7-8.     RHIPIDOMELLA  BURLINGTONENSIS   (Hall) p.  149 

Interior  views  of  the  pedicle  and  brachial  valves  of  one  individual. 
(W.  M.,  No.  7858.) 

Burlington  limestone,  Burlington,  loiva. 

Figs.  9-10.     RHIPIDOMELLA  DUBIA  (Hall) p.  160 

Interior  views  of  a  pedicle  and  a  brachial  valve.  (W.  M.,  Nos. 
7846  and  11927.) 

Salem  limestone,  Colesburg,  Kentucky,  and  Spergen  Hill, 
Indiana. 

Fig.  11.     SCHELLWIENELLA  INFLATA  (White  and  Whitfield) . p.     59 

View  of  an  internal  cast  of  a  pedicle  valve.     (W.  M.,  No.  14759.) 
Kinderhook,  Bed  No.  7,  Burlington,  Iowa. 

Figs.  12-13.     PRODUCTUS  INDIANENSIS  Hall p.  131 

Pedicle  and  lateral  views  of  the  holotype.     (A.  M.  N.  H.,  No.  5087) 
Salem   limestone,   Spergen   Hill,  Indiana. 

Figs.  14-17     PRODUCTUS  MESIALIS  Hall p.  112 

14-16.  Pedicle,  posterior  and  lateral  views  of  a  pedicle  valve.  17. 
View  of  an  impression  of  the  exterior  of  a  brachial  valve.  Co- 
types.  (A.  M.  N.  H.,  No.  5090.) 

Keokuk  limestone,  Nauvoo,  Illinois. 

Figs.  18-20.     PRODUCTELLA  SUBL^VIS  n.  sp p.  102 

18-19.  Views  of  the  more  or  less  modified  internal  casts  of  two 
pedicle  valves.  20.  View  of  an  incomplete  external  impression 
of  a  brachial  valve.  (W.  M.,  No.  10558.) 

Kinderhook  sandstone,  Kinderhook,  Illinois. 

Figs.  21-22.     CHONOPECTUS  FISCHERI    (Norwood  and  Pratten) p.     96 

21.  View  of  the  internal  cast  of  a  large  pedicle  valve.  22.  View 
of  an  impression  of  the  pedicle  valve  showing  the  cardinal 
spines.  (W.  M.,  No.  14779.) 

Chonopectus  sandstone,  Burlington,  lozva. 


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ILLINOIS    STATE   GEOLOGICAL    SURVEY.  MONOGRAPH  No.  1.    PLATE  LXXXIII. 


8 


12 


13 


1O 


16 


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